CVE-2026-42770

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.

Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts.

When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared.

A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack).

The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership. Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts. When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared. A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack). The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.

Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts.

When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared.

A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack).

The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

OpenSSL is a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols.

Security Fix(es):

Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms.

Impact summary: The heap buffer over-read may crash the application (Denial of Service) or to load into the decoded ASN.1 object contents of memory beyond the end of the input buffer. More typically such ASN.1 elements would instead be truncated.

An integer truncation in OpenSSL's ASN.1 decoder causes the content length of an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the worst case the truncated length is treated as a request to scan the binary content for a terminating zero byte, possibly causing OpenSSL to read either less than or beyond the end of the allocated buffer.

Applications that pass attacker-supplied data to d2i_X509(), d2i_PKCS7(), or any other d2i_* decoding function are affected. OpenSSL's own command-line tools are not vulnerable, as data read through the BIO layer is checked before it reaches the affected code. The issue only affects 64-bit Unix and Unix-like platforms; 32-bit platforms and 64-bit Windows are not affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-34180)

Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input validation on the cipher and tag length fields of AuthEnvelopedData containers, leading to various potential compromises.

Impact Summary: Attackers making use of these vulnerabilities may achieve key-equivalent functionality for a given CMS recipient and/or bypass integrity validation for a given message.

In one use case, an attacker may send a CMS message containing AuthEnvelopedData with the cipher specified as a non-AEAD cipher. OpenSSL erroneously allows this selection, and attempts to decrypt and validate the message.

An on-path attacker who captures one legitimate AES-GCM AuthEnvelopedData addressed to the victim can re-emit it with the recipientInfos set left byte-for-byte intact, so the victim's private key still unwraps the genuine CEK (the content-encryption key), but with the inner OID rewritten to AES-256-OFB (Output Feedback Mode, an unauthenticated keystream mode) and with an attacker-chosen IV and ciphertext. The victim initializes AES-256-OFB under the real CEK, never consults the MAC field, and CMS_decrypt() returns success.

If the application under attack responds to the attacker with any indicator showing success or failure of the decryption effort, it is possible for the attacker to use this as an oracle to obtain key equivalent functionality for the CEK used for the chosen recipient of the message.

In another use case, an attacker can reduce the tag length of the chosen AEAD cipher for a given AuthEnvelopedData container to be a single byte long, allowing an attacker to brute force CMS decryption, producing an integrity bypass for applications that trust CMS_decrypt() to reject modified content.

The FIPS modules are not affected by this issue.(CVE-2026-34182)

Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption.

Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service.

The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present.

An attacker who supplies such a CMS message to an application performing password-based CMS decryption…

OpenSSL is a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols.

Security Fix(es):

Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms.

Impact summary: The heap buffer over-read may crash the application (Denial of Service) or to load into the decoded ASN.1 object contents of memory beyond the end of the input buffer. More typically such ASN.1 elements would instead be truncated.

An integer truncation in OpenSSL's ASN.1 decoder causes the content length of an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the worst case the truncated length is treated as a request to scan the binary content for a terminating zero byte, possibly causing OpenSSL to read either less than or beyond the end of the allocated buffer.

Applications that pass attacker-supplied data to d2i_X509(), d2i_PKCS7(), or any other d2i_* decoding function are affected. OpenSSL's own command-line tools are not vulnerable, as data read through the BIO layer is checked before it reaches the affected code. The issue only affects 64-bit Unix and Unix-like platforms; 32-bit platforms and 64-bit Windows are not affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-34180)

Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input validation on the cipher and tag length fields of AuthEnvelopedData containers, leading to various potential compromises.

Impact Summary: Attackers making use of these vulnerabilities may achieve key-equivalent functionality for a given CMS recipient and/or bypass integrity validation for a given message.

In one use case, an attacker may send a CMS message containing AuthEnvelopedData with the cipher specified as a non-AEAD cipher. OpenSSL erroneously allows this selection, and attempts to decrypt and validate the message.

An on-path attacker who captures one legitimate AES-GCM AuthEnvelopedData addressed to the victim can re-emit it with the recipientInfos set left byte-for-byte intact, so the victim's private key still unwraps the genuine CEK (the content-encryption key), but with the inner OID rewritten to AES-256-OFB (Output Feedback Mode, an unauthenticated keystream mode) and with an attacker-chosen IV and ciphertext. The victim initializes AES-256-OFB under the real CEK, never consults the MAC field, and CMS_decrypt() returns success.

If the application under attack responds to the attacker with any indicator showing success or failure of the decryption effort, it is possible for the attacker to use this as an oracle to obtain key equivalent functionality for the CEK used for the chosen recipient of the message.

In another use case, an attacker can reduce the tag length of the chosen AEAD cipher for a given AuthEnvelopedData container to be a single byte long, allowing an attacker to brute force CMS decryption, producing an integrity bypass for applications that trust CMS_decrypt() to reject modified content.

The FIPS modules are not affected by this issue.(CVE-2026-34182)

Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption.

Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service.

The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present.

An attacker who supplies such a CMS message to an application performing password-based CMS decryption…

EDK II is a modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications.

Security Fix(es):

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.

Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts.

When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared.

A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack).

The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are affected by this issue.(CVE-2026-42770)

EDK II is a modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications.

Security Fix(es):

Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption.

Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service.

The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present.

An attacker who supplies such a CMS message to an application performing password-based CMS decryption can trigger an application crash, leading to a Denial of Service.

Applications that process password-encrypted CMS messages may be affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-42766)

Issue summary: An attacker-controlled CMP (Certificate Management Protocol) server could trigger a NULL pointer dereference in a CMP client application.

Impact summary: A NULL pointer dereference causes a crash of the application and a Denial of Service.

An attacker controlling a CMP server (or acting as a man-in-the-middle) could craft a CMP response containing a CRMF (Certificate Request Message Format) CertRepMessage with an EncryptedValue structure where the symmAlg field has an algorithm OID but no parameters field. When the OpenSSL CMP client processes this response, the NULL dereference occurs, causing a crash of the CMP client.

Applications that process untrusted CMP/CRMF messages may be affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-42767)

Issue summary: The CMS_decrypt and PKCS7_decrypt functions are vulnerable to Bleichenbacher-style attack when an attacker is able to provide the CMS or S/MIME messages and observe the error code and/or decryption output.

Impact summary: The Bleichenbacher-style attack allows an attacker to use the victim's vulnerable application as a way to decrypt or sign messages with the victim's private RSA key.

The attack is possible in 2 variants.

1. The decryption API (CMS_decrypt(), PKCS7_decrypt()) is used without providing the recipient certificate. In this case OpenSSL iterates over every KeyTransRecipientInfo (KTRI) without stopping at the first success.

An attacker who authors a message with two KTRI entries — the first one wrapping a real CEK under the victim's public key, the second with an arbitrary probe ciphertext — obtains opportunity to iterate the 2nd KTRI to get a valid PKCS#1 v1.5 padding if the error code of the application is available.

That is a Bleichenbacher oracle (Bleichenbacher, CRYPTO '98): an adaptive-chosen-ciphertext side channel from which the attacker decrypts any RSA ciphertext to the victim's key or forges any PKCS#1 v1.5 signature under it.

2. When the decryption API (CMS_decrypt(), PKCS7_decrypt()) is provided with the recipient certificate, and the recipient is not found, a random key is substituted.

An attacker who authors a message and is able to compare both error code and the result of the decryption, can mount a Bleichenbacher oracle.

We are not aware of any applications that provide a remote attacker an opportunity to mount an attack described in these scenarios. We consider the existence of such application very unlikely, and for this reason this CVE has been evaluated as Low severity.

To avoid these attacks, when RSA PKCS#1 v1.5 Key Transport is in use, the invoked EVP_PKEY_decrypt() will use the implicit rejection mechanism described in draft-irtf-cfrg-rsa-guidance. In previous OpenSSL releases the implicit rejection was…

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, as well as a full-strength general-purpose cryptography library.

Security Fix(es):

• openssl: OpenSSL: Heap buffer overflow due to signed integer overflow in Unicode output sizing (CVE-2026-7383)

• openssl: OpenSSL: Denial of Service due to heap out-of-bounds read in CMS password-based decryption (CVE-2026-9076)

• openssl: OpenSSL: Heap buffer over-read in ASN.1 decoding can lead to denial of service or information disclosure. (CVE-2026-34180)

• openssl: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (CVE-2026-34181)

• openssl: CMS AuthEnvelopedData Processing May Accept Forged Messages (CVE-2026-34182)

• openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (CVE-2026-34183)

• openssl: NULL pointer dereference in QUIC server initial packet handling (CVE-2026-42764)

• openssl: Possible NULL Dereference in Password-Based CMS Decryption (CVE-2026-42766)

• openssl: NULL Pointer Dereference in CRMF EncryptedValue Decryption (CVE-2026-42767)

• openssl: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (CVE-2026-42768)

• openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (CVE-2026-42769)

• openssl: FFC-DH Peer Validation Uses Attacker-Supplied q (CVE-2026-42770)

• openssl: AES-OCB IV Ignored on EVP_Cipher() Path (CVE-2026-45445)

• openssl: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (CVE-2026-45446)

• openssl: Heap Use-After-Free in OpenSSL PKCS7_verify() (CVE-2026-45447)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, as well as a full-strength general-purpose cryptography library.

Security Fix(es):

• openssl: OpenSSL: Heap buffer overflow due to signed integer overflow in Unicode output sizing (CVE-2026-7383)

• openssl: OpenSSL: Denial of Service due to heap out-of-bounds read in CMS password-based decryption (CVE-2026-9076)

• openssl: OpenSSL: Heap buffer over-read in ASN.1 decoding can lead to denial of service or information disclosure. (CVE-2026-34180)

• openssl: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (CVE-2026-34181)

• openssl: CMS AuthEnvelopedData Processing May Accept Forged Messages (CVE-2026-34182)

• openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (CVE-2026-34183)

• openssl: NULL pointer dereference in QUIC server initial packet handling (CVE-2026-42764)

• openssl: Possible NULL Dereference in Password-Based CMS Decryption (CVE-2026-42766)

• openssl: NULL Pointer Dereference in CRMF EncryptedValue Decryption (CVE-2026-42767)

• openssl: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (CVE-2026-42768)

• openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (CVE-2026-42769)

• openssl: FFC-DH Peer Validation Uses Attacker-Supplied q (CVE-2026-42770)

• openssl: AES-OCB IV Ignored on EVP_Cipher() Path (CVE-2026-45445)

• openssl: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (CVE-2026-45446)

• openssl: Heap Use-After-Free in OpenSSL PKCS7_verify() (CVE-2026-45447)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership. Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts. When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared. A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack). The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, as well as a full-strength general-purpose cryptography library.

Security Fix(es):

• openssl: OpenSSL: Heap buffer overflow due to signed integer overflow in Unicode output sizing (CVE-2026-7383)
• openssl: OpenSSL: Denial of Service due to heap out-of-bounds read in CMS password-based decryption (CVE-2026-9076)
• openssl: OpenSSL: Heap buffer over-read in ASN.1 decoding can lead to denial of service or information disclosure. (CVE-2026-34180)
• openssl: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (CVE-2026-34181)
• openssl: CMS AuthEnvelopedData Processing May Accept Forged Messages (CVE-2026-34182)
• openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (CVE-2026-34183)
• openssl: NULL pointer dereference in QUIC server initial packet handling (CVE-2026-42764)
• openssl: Possible NULL Dereference in Password-Based CMS Decryption (CVE-2026-42766)
• openssl: NULL Pointer Dereference in CRMF EncryptedValue Decryption (CVE-2026-42767)
• openssl: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (CVE-2026-42768)
• openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (CVE-2026-42769)
• openssl: FFC-DH Peer Validation Uses Attacker-Supplied q (CVE-2026-42770)
• openssl: AES-OCB IV Ignored on EVP_Cipher() Path (CVE-2026-45445)
• openssl: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (CVE-2026-45446)
• openssl: Heap Use-After-Free in OpenSSL PKCS7_verify() (CVE-2026-45447)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, as well as a full-strength general-purpose cryptography library.

Security Fix(es):

• openssl: OpenSSL: Heap buffer overflow due to signed integer overflow in Unicode output sizing (CVE-2026-7383)
• openssl: OpenSSL: Denial of Service due to heap out-of-bounds read in CMS password-based decryption (CVE-2026-9076)
• openssl: OpenSSL: Heap buffer over-read in ASN.1 decoding can lead to denial of service or information disclosure. (CVE-2026-34180)
• openssl: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (CVE-2026-34181)
• openssl: CMS AuthEnvelopedData Processing May Accept Forged Messages (CVE-2026-34182)
• openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (CVE-2026-34183)
• openssl: NULL pointer dereference in QUIC server initial packet handling (CVE-2026-42764)
• openssl: Possible NULL Dereference in Password-Based CMS Decryption (CVE-2026-42766)
• openssl: NULL Pointer Dereference in CRMF EncryptedValue Decryption (CVE-2026-42767)
• openssl: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (CVE-2026-42768)
• openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (CVE-2026-42769)
• openssl: FFC-DH Peer Validation Uses Attacker-Supplied q (CVE-2026-42770)
• openssl: AES-OCB IV Ignored on EVP_Cipher() Path (CVE-2026-45445)
• openssl: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (CVE-2026-45446)
• openssl: Heap Use-After-Free in OpenSSL PKCS7_verify() (CVE-2026-45447)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.

Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts.

When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared.

A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack).

The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.

Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts.

When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared.

A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack).

The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

The updated packages fix security vulnerabilities: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion. (CVE-2026-7383) Out-of-Bounds Read in CMS Password-Based Decryption. (CVE-2026-9076) Heap Buffer Over-read in ASN.1 Content Parsing. (CVE-2026-34180) PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys. (CVE-2026-34181) CMS AuthEnvelopedData Processing May Accept Forged Messages. (CVE-2026-34182) Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler. (CVE-2026-34183) NULL Pointer Dereference in QUIC Server Initial Packet Handling. (CVE-2026-42764) Possible NULL Dereference in Password-Based CMS Decryption. (CVE-2026-42766) NULL Pointer Dereference in CRMF EncryptedValue Decryption. (CVE-2026-42767) Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt(). (CVE-2026-42768) Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate. (CVE-2026-42769) FFC-DH Peer Validation Uses Attacker-Supplied q. (CVE-2026-42770) AES-OCB IV Ignored on EVP_Cipher() Path. (CVE-2026-45445) Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes. (CVE-2026-45446) Heap Use-After-Free in the PKCS7_verify(). (CVE-2026-45447)

These are all security issues fixed in the libopenssl-3-devel-3.5.3-6.1 package on the GA media of openSUSE Tumbleweed.

This update for openssl-3 fixes the following issues

• CVE-2026-2673: TLS 1.3 servers may choose unexpected key agreement group (bsc#1259652).
• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-34183: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (bsc#1266345).
• CVE-2026-42764: NULL pointer dereference in QUIC server initial packet handling (bsc#1266347).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42767: NULL Pointer Dereference in CRMF EncryptedValue Decryption (bsc#1266350).
• CVE-2026-42768: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (bsc#1266351).
• CVE-2026-42769: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (bsc#1266352).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2024-41996: DHEATATTACK: Validating the order of the public keys in the Diffie-Hellman Key Agreement Protocol, when an approved safe prime is used, allows remote attackers to trigger expensive server-side DHE (bsc#1230698).
• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-28390: NULL pointer dereference during processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo (bsc#1261678).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-2673: TLS 1.3 servers may choose unexpected key agreement group (bsc#1259652).
• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-34183: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (bsc#1266345).
• CVE-2026-42764: NULL pointer dereference in QUIC server initial packet handling (bsc#1266347).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42767: NULL Pointer Dereference in CRMF EncryptedValue Decryption (bsc#1266350).
• CVE-2026-42768: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (bsc#1266351).
• CVE-2026-42769: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (bsc#1266352).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-2673: TLS 1.3 servers may choose unexpected key agreement group (bsc#1259652).
• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-34183: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (bsc#1266345).
• CVE-2026-42764: NULL pointer dereference in QUIC server initial packet handling (bsc#1266347).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42767: NULL Pointer Dereference in CRMF EncryptedValue Decryption (bsc#1266350).
• CVE-2026-42768: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (bsc#1266351).
• CVE-2026-42769: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (bsc#1266352).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34182: CMS AuthEnvelopedData Processing May Accept Forged Messages (bsc#1266344).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).

This update for openssl-3 fixes the following issues

• CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340).
• CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341).
• CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342).
• CVE-2026-34181: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (bsc#1266343).
• CVE-2026-34183: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler (bsc#1266345).
• CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349).
• CVE-2026-42767: NULL Pointer Dereference in CRMF EncryptedValue Decryption (bsc#1266350).
• CVE-2026-42768: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() (bsc#1266351).
• CVE-2026-42769: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate (bsc#1266352).
• CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q (bsc#1266353).
• CVE-2026-45445: AES-OCB IV Ignored on EVP_Cipher() Path (bsc#1266355).
• CVE-2026-45446: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes (bsc#1266356).
• CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357).