Every CVE Search/ Get API key

CVE-2026-71888

CMS AuthenticatedData exposes attacker-inserted authAttrs when digestAlgorithm is absent

8.7 HighFix available

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
High
Availability
None

Exploit likelihood

0.11%Unchanged since Oct 3, 2026
90%50%10%1%

What each source reports

CVE List Score used 8.7

CMS AuthenticatedData exposes attacker-inserted authAttrs when digestAlgorithm is absent

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
CVE-2026-71888
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Weakness
CWE-354
Updated
2026-11-02
EUVDEUVD-2026-91991 8.7

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
EUVD-2026-91991
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Updated
2026-11-02
GitHub AdvisoriesGHSA-j453-27jp-4cph 8.7

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a...

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
GHSA-j453-27jp-4cph
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
Weakness
CWE-354
Updated
2026-11-02
NVD 8.7

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
CVE-2026-71888
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
Weakness
CWE-354
Updated
2026-11-02
OSV 8.7

CMS AuthenticatedData exposes attacker-inserted authAttrs when digestAlgorithm is absent

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
CVE-2026-71888
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Weakness
CWE-354
Updated
2026-11-04
OSVDEBIAN-CVE-2026-71888 8.7

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
DEBIAN-CVE-2026-71888
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
Updated
2026-11-02
Show 10 moreShow less
OSVOESA-2026-4243 8.7

bouncycastle security update

The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework.

Security Fix(es):

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).(CVE-2026-71888)

Record
OESA-2026-4243
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
OSVOESA-2026-4244 8.7

bouncycastle security update

The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework.

Security Fix(es):

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).(CVE-2026-71888)

Record
OESA-2026-4244
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
OSVOESA-2026-4245 8.7

bouncycastle security update

The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework.

Security Fix(es):

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).(CVE-2026-71888)

Record
OESA-2026-4245
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
OSVOESA-2026-4246 8.7

bouncycastle security update

The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework.

Security Fix(es):

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).(CVE-2026-71888)

Record
OESA-2026-4246
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
OSVUBUNTU-CVE-2026-71888 8.7

In Bouncy Castle for Java before 1.86, the streaming CMS AuthenticatedData parser accepted a message whose digestAlgorithm and authAttrs fields disagreed about whether authenticated attributes were present. RFC 5652 sec. 9.1 pairs the two, requiring that authAttrs be present whenever digestAlgorithm is, and sec. 9.2 makes the MAC cover the DER encoding of authAttrs when they are present and the eContent OCTET STRING directly when they are not. CMSAuthenticatedDataParser has to choose between those two in its constructor, before it can reach authAttrs, which comes later in the SEQUENCE, so it chose on digestAlgorithm alone: for a message with digestAlgorithm absent but authAttrs present it verified the content MAC and then returned the attributes through getAuthAttrs() as though they had been authenticated, when the MAC had never covered them. An attacker able to modify a message in transit could insert an authenticated attribute, such as an RFC 2634 ESSSecurityLabel, into an otherwise valid message while holding neither the key-encryption key nor the content-MAC key, and an application taking an authorization, routing or labelling decision from those attributes would act on attacker-chosen values. The content itself remained MAC-bound. asn1.cms.AuthenticatedData now rejects the mismatched pairing when parsing and CMSAuthenticatedDataParser cross-checks the two fields once authAttrs is read. This is a variant of CVE-2026-59642, which bound the content to the MAC for messages that legitimately carry authAttrs, and which does not address this case. This issue also affects Bouncy Castle for Java LTS before 2.73.13, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series), and bcutil-fips 2.0.8 (2.0.X series) and 2.1.8 (2.1.X series).

Record
UBUNTU-CVE-2026-71888
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Updated
2026-11-02
OSVopenSUSE-SU-2026:12090-1 No score

bouncycastle-1.86-1.1 on GA media

These are all security issues fixed in the bouncycastle-1.86-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2026:12090-1
Updated
2026-11-02
OSVopenSUSE-SU-2026:22169-1 No score

Security update for bouncycastle

This update for bouncycastle fixes the following issues:

Update to 1.86:

  • CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion (bsc#1284075).
  • CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).
  • CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel attacks (bsc#1284065).
  • CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks (bsc#1284205).
  • CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group message interception (bsc#1284165).
  • CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and identity spoofing (bsc#1284212).
  • CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust context spoofing (bsc#1284213).
  • CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute injection (bsc#1284215).
  • CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses (bsc#1284218).
  • CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and session takeover (bsc#1284219).
  • CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses (bsc#1284220).
  • CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived content keys (bsc#1284221).
  • CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors and integrity check bypasses (bsc#1284222).
  • CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource exhaustion (bsc#1284224).
Record
openSUSE-SU-2026:22169-1
Updated
2026-11-02
OSVROOT-APP-MAVEN-CVE-2026-71888 No score

CVE-2026-71888 in org.bouncycastle:bcpkix-jdk15on - Patched by Root

Root has patched CVE-2026-71888 in the org.bouncycastle:bcpkix-jdk15on package for Root:Maven. Multiple fixed versions available.

Record
ROOT-APP-MAVEN-CVE-2026-71888
Updated
2026-11-02
OSVSUSE-SU-2026:24461-1 No score

Security update for bouncycastle

This update for bouncycastle fixes the following issues:

Update to 1.86:

  • CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion (bsc#1284075).
  • CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).
  • CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel attacks (bsc#1284065).
  • CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks (bsc#1284205).
  • CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group message interception (bsc#1284165).
  • CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and identity spoofing (bsc#1284212).
  • CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust context spoofing (bsc#1284213).
  • CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute injection (bsc#1284215).
  • CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses (bsc#1284218).
  • CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and session takeover (bsc#1284219).
  • CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses (bsc#1284220).
  • CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived content keys (bsc#1284221).
  • CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors and integrity check bypasses (bsc#1284222).
  • CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource exhaustion (bsc#1284224).
Record
SUSE-SU-2026:24461-1
Updated
2026-11-04
OSVSUSE-SU-2026:4797-1 No score

Security update for bouncycastle

This update for bouncycastle fixes the following issues:

  • CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion (bsc#1284075).
  • CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).
  • CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel attacks (bsc#1284065).
  • CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks (bsc#1284205).
  • CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group message interception (bsc#1284165).
  • CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and identity spoofing (bsc#1284212).
  • CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust context spoofing (bsc#1284213).
  • CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute injection (bsc#1284215).
  • CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses (bsc#1284218).
  • CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and session takeover (bsc#1284219).
  • CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses (bsc#1284220).
  • CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived content keys (bsc#1284221).
  • CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors and integrity check bypasses (bsc#1284222).
  • CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource exhaustion (bsc#1284224).

Changes for bouncycastle:

  • Updated to version 1.86.
Record
SUSE-SU-2026:4797-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
bouncycastle
Debian:12
 All versions, plus listed versions
1.72-21.77-11.80-11.80-21.80-31.86-1
 None known
bouncycastle
Debian:13
 All versions, plus listed versions
1.80-31.86-1
 None known
bouncycastle
Debian:14
 before 1.86-1, plus listed versions
1.80-3
1.86-1
bouncycastle
openEuler:22.03-LTS-SP4
 before 1.67-3.oe2203sp4
1.67-3.oe2203sp4
bouncycastle
openEuler:24.03-LTS-SP1
 before 1.67-3.oe2403sp1
1.67-3.oe2403sp1
bouncycastle
openEuler:24.03-LTS-SP3
 before 1.67-3.oe2403sp3
1.67-3.oe2403sp3
bouncycastle
openEuler:24.03-LTS-SP4
 before 1.67-3.oe2403sp4
1.67-3.oe2403sp4
org.bouncycastle:bcpkix-jdk15on
Root:Maven
 before 1.69-aikido.1
1.69-aikido.11.68-aikido.21.70-aikido.41.64-aikido.5
io.root.org.bouncycastle:bcpkix-jdk15on
Root:Maven
 before 1.69-root.io.1
1.69-root.io.11.68-root.io.21.70-root.io.41.64-root.io.5
bouncycastle
SUSE:Linux Enterprise Server 16.0
From an advisory covering 14 CVEs
 before 1.86-160000.1.1
1.86-160000.1.1
Show 21 moreShow less
Affected packages
PackageAffectedFixed
bouncycastle
SUSE:Linux Enterprise Server for SAP applications 16.0
From an advisory covering 14 CVEs
 before 1.86-160000.1.1
1.86-160000.1.1
bouncycastle
SUSE:Linux Enterprise Module for Development Tools 15 SP7
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server 15 SP4-LTSS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server 15 SP5-LTSS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server 15 SP6-LTSS
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server for SAP Applications 15 SP4
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server for SAP Applications 15 SP5
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
SUSE:Linux Enterprise Server for SAP Applications 15 SP6
From an advisory covering 14 CVEs
 before 1.86-150200.3.41.1
1.86-150200.3.41.1
bouncycastle
Ubuntu:Pro:16.04:LTS
 All versions, plus listed versions
1.49+dfsg-3ubuntu11.51-4ubuntu11.51-4ubuntu1+esm1
 None known
bouncycastle
Ubuntu:Pro:18.04:LTS
 All versions, plus listed versions
1.57-11.58-11.59-11.59-1ubuntu0.1~esm1
 None known
bouncycastle
Ubuntu:Pro:20.04:LTS
 All versions, plus listed versions
1.61-11.61-1ubuntu0.1~esm1
 None known
bouncycastle
Ubuntu:Pro:22.04:LTS
 All versions, plus listed versions
1.68-21.68-41.68-51.68-5ubuntu0.1~esm1
 None known
bouncycastle
Ubuntu:Pro:24.04:LTS
 All versions, plus listed versions
1.72-21.77-11.77-1ubuntu0.1~esm1
 None known
bouncycastle
Ubuntu:26.10
 All versions, plus listed versions
1.80-3
 None known
bouncycastle
Ubuntu:26.04:LTS
 All versions, plus listed versions
1.80-3
 None known
bouncycastle
openSUSE:Tumbleweed
From an advisory covering 14 CVEs
 before 1.86-1.1
1.86-1.1
bouncycastle
openSUSE:Leap 16.0
From an advisory covering 14 CVEs
 before 1.86-160000.1.1
1.86-160000.1.1

History

History
RecordedChangedSources
affected
affected, aliases, facts, referencesOSV
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-71888 is a high vulnerability (CVSS 8.7) in Legion Of The Bouncy Castle Inc. Bc-fja, published October 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.11%, the 1st percentile. Fixed in bouncycastle 1.86-1.

References

Show 41 moreShow less
Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open