CVE-2026-42011

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

Please update the gnutls packages to provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

Security Fix(es):

• gnutls: Add more checks to DTLS reassembly (CVE-2026-33846)
• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram (CVE-2026-33845)
• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name constraints (CVE-2026-3833)
• gnutls: Fix intersecting empty constraints (CVE-2026-42011)

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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

Security Fix(es):

• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram (CVE-2026-33845)
• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name constraints (CVE-2026-3833)
• gnutls: Fix intersecting empty name constraints (CVE-2026-42011)
• gnutls: Denial of Service via heap buffer overflow in DTLS handshake fragment reassembly (CVE-2026-33846)

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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

Security Fix(es):

• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram (CVE-2026-33845)
• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name constraints (CVE-2026-3833)
• gnutls: Fix intersecting empty name constraints (CVE-2026-42011)
• gnutls: Denial of Service via heap buffer overflow in DTLS handshake fragment reassembly (CVE-2026-33846)

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.

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

Please update the gnutls packages to provide the GNU Transport Layer Security (GnuTLS) library, which implements cryptographic algorithms and protocols such as SSL, TLS, and DTLS.

Security Fix(es):

• gnutls: Add more checks to DTLS reassembly (CVE-2026-33846)
• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram (CVE-2026-33845)
• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name constraints (CVE-2026-3833)
• gnutls: Fix intersecting empty constraints (CVE-2026-42011)

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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library,
which implements cryptographic algorithms and protocols such as SSL, TLS, and
DTLS.

Security Fix(es):

• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram

(CVE-2026-33845)

• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name

constraints (CVE-2026-3833)

• gnutls: Fix intersecting empty name constraints (CVE-2026-42011)
• gnutls: Denial of Service via heap buffer overflow in DTLS handshake

fragment reassembly (CVE-2026-33846)

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.

The gnutls packages provide the GNU Transport Layer Security (GnuTLS) library,
which implements cryptographic algorithms and protocols such as SSL, TLS, and
DTLS.

Security Fix(es):

• gnutls: Fix qsort comparator in DTLS reassembly (CVE-2026-42009)
• gnutls: Fix crashing on an underflow with a DTLS datagram (CVE-2026-33845)
• gnutls: Fix RSA-PSK identity truncation (CVE-2026-42010)
• gnutls: Fix case-sensitivity of domain name comparison in name constraints (CVE-2026-3833)
• gnutls: Fix intersecting empty name constraints (CVE-2026-42011)
• gnutls: Denial of Service via heap buffer overflow in DTLS handshake fragment reassembly (CVE-2026-33846)

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.

• CVE-2026-33846: DTLS handshake reassembly add more checks (buffers.c)
• CVE-2026-42009: DTLS reorder qsort with duplicate sequence numbers
• CVE-2026-42011: X.509 name constraints intersection of empty constraints
• CVE-2026-42012: URI/SRV SAN preclude CN fallback
• CVE-2026-42013: prevent fallback on oversized SAN
• CVE-2026-42014: PKCS#11 token set_pin UAF + leak
• CVE-2026-5260: PKCS#11 RSA short-ciphertext overread; ciphertext must match modulus size
• CVE-2026-42015: PKCS#12 bag-element off-by-one bound check

• CVE-2026-33846: DTLS handshake reassembly add more checks (buffers.c)
• CVE-2026-42009: DTLS reorder qsort with duplicate sequence numbers
• CVE-2026-42011: X.509 name constraints intersection of empty constraints
• CVE-2026-42012: URI/SRV SAN preclude CN fallback
• CVE-2026-42013: prevent fallback on oversized SAN
• CVE-2026-42014: PKCS#11 token set_pin UAF + leak
• CVE-2026-5260: PKCS#11 RSA short-ciphertext overread; ciphertext must match modulus size
• CVE-2026-42015: PKCS#12 bag-element off-by-one bound check

• CVE-2026-33846: fix heap buffer overflow in DTLS handshake fragment reassembly by validating message-length consistency and bounding the fragment write against the destination buffer capacity
• CVE-2026-42009: fix undefined behaviour in DTLS packet ordering by making the handshake_compare qsort comparator return 0 for equal sequence numbers
• CVE-2026-42011: fix name constraints bypass by no longer short-circuiting the intersection of an empty permitted set, so later permitted constraints are still enforced
• CVE-2026-42012: fix certificate verification bypass by making URI and SRV subjectAltName entries preclude the legacy CN fallback hostname check
• CVE-2026-42013: fix certificate verification bypass by preventing CN and DN-email fallback when a subjectAltName entry is oversized
• CVE-2026-5260: fix heap overread in RSA key exchange by rejecting a ciphertext whose size does not match the RSA modulus
• CVE-2026-42014: fix use-after-free and leak in gnutls_pkcs11_token_set_pin when changing the security officer PIN

• CVE-2026-33846: fix heap buffer overflow in DTLS handshake fragment reassembly by validating message-length consistency and bounding the fragment write against the destination buffer capacity
• CVE-2026-42009: fix undefined behaviour in DTLS packet ordering by making the handshake_compare qsort comparator return 0 for equal sequence numbers
• CVE-2026-42011: fix name constraints bypass by no longer short-circuiting the intersection of an empty permitted set, so later permitted constraints are still enforced
• CVE-2026-42012: fix certificate verification bypass by making URI and SRV subjectAltName entries preclude the legacy CN fallback hostname check
• CVE-2026-42013: fix certificate verification bypass by preventing CN and DN-email fallback when a subjectAltName entry is oversized
• CVE-2026-5260: fix heap overread in RSA key exchange by rejecting a ciphertext whose size does not match the RSA modulus
• CVE-2026-42014: fix use-after-free and leak in gnutls_pkcs11_token_set_pin when changing the security officer PIN
• CVE-2026-42015: fix off-by-one out-of-bounds write when appending an element to a PKCS#12 bag that already holds the maximum number of elements

• SECURITY UPDATE: name-constraints bypass with excluded-only parent CA
  • debian/patches/CVE-2026-42011.patch: take permitted name constraints into account when a prior CA in the chain carried only excluded constraints, so a constrained sub-CA can no longer issue certificates outside its permitted scope, in lib/x509/name_constraints.c.
  • CVE-2026-42011
• SECURITY UPDATE: CN fallback not precluded by URI SAN
  • debian/patches/CVE-2026-42012.patch: treat a URI subject alternative name as precluding the fallback to Common Name hostname matching, per RFC 6125 6.4.4, in lib/x509/hostname-verify.c.
  • CVE-2026-42012
• SECURITY UPDATE: CN/DN fallback not precluded by oversized SAN
  • debian/patches/CVE-2026-42013.patch: keep the CN (hostname) and DN-email fallbacks disabled when a subject alternative name is oversized instead of silently ignoring it, per RFC 6125 6.4.4, in lib/x509/hostname-verify.c and lib/x509/email-verify.c.
  • CVE-2026-42013
• SECURITY UPDATE: PKCS#12 bag out-of-bounds write
  • debian/patches/CVE-2026-42015.patch: fix an off-by-one in the PKCS#12 bag element bounds check that allowed writing past the 32-element array, in lib/x509/pkcs12_bag.c.
  • CVE-2026-42015

• SECURITY UPDATE: Name constraints bypass when prior CAs have only excluded constraints
  • debian/patches/CVE-2026-42011.patch: remove the empty-permitted early return in name_constraints_node_list_intersect in lib/x509/name_constraints.c so permitted name constraints of a subsequent CA still propagate when previous CAs only carried excluded constraints; also backport the upstream regression suites to tests/name-constraints-merge.c
  • CVE-2026-42011
• SECURITY UPDATE: Certificate validation bypass via oversized subject alternative name
  • debian/patches/CVE-2026-42013.patch: refactor the CN and DN-email fallback logic and disable the fallback when gnutls_x509_crt_get_subject_alt_name reports an oversized SAN (GNUTLS_E_SHORT_MEMORY_BUFFER) in gnutls_x509_crt_check_hostname2 and gnutls_x509_crt_check_email (lib/x509/hostname-verify.c, lib/x509/email-verify.c); also backport the upstream regression tests to tests/hostname-check.c and tests/cert-tests/email (with tests/cert-tests/email-certs/oversized-san.pem)
  • CVE-2026-42013
• SECURITY UPDATE: CN fallback not precluded by URI or SRV subject alternative names
  • debian/patches/CVE-2026-42012.patch: add GNUTLS_SAN_URI and GNUTLS_SAN_OTHERNAME_SRV to the PRECLUDES_CN_FALLBACK macro in lib/x509/hostname-verify.c so certificates presenting URI or SRV SANs no longer allow hostname matching against the common name per RFC 6125 6.4.4; backport SRV virtual-SAN awareness (lib/includes/gnutls/gnutls.h.in, lib/x509/common.h, lib/x509/virt-san.c, lib/x509/output.c, lib/x509/x509.c) and the get_alt_name othername virtualization fix so SRV othernames are recognized on 3.6.13; also backport the upstream regression tests to tests/hostname-check.c
  • CVE-2026-42012

• Rebased onto the vendor 3.3.29-9.0.3.el7_9 sources
• CVE-2026-5260: guard PKCS#11 RSA decryption against short-ciphertext heap overread (TuxCare fix retained)
• CVE-2026-42014 and CVE-2026-42015 are fixed by the vendor in this build
• CVE-2026-42011 is not applicable to this baseline per the vendor assessment
• CVE-2026-33845, CVE-2026-33846, CVE-2026-3833, CVE-2026-42009, CVE-2026-42012 and CVE-2026-42013 are now fixed by the vendor; the TuxCare duplicates are dropped
• CVE-2026-3833 follow-up: the vendor's email_matches() no longer matches a bare-domain rfc822Name against a bare-domain constraint of the same length, which 3.3.29 did; restore that comparison, case-insensitively, and add the assertions to tests/name-constraints.c

• Rebased onto the vendor 3.3.29-9.0.3.el7_9 sources
• CVE-2026-5260: guard PKCS#11 RSA decryption against short-ciphertext heap overread (TuxCare fix retained)
• CVE-2026-42014 and CVE-2026-42015 are fixed by the vendor in this build
• CVE-2026-42011 is not applicable to this baseline per the vendor assessment
• CVE-2026-33845, CVE-2026-33846, CVE-2026-3833, CVE-2026-42009, CVE-2026-42012 and CVE-2026-42013 are now fixed by the vendor; the TuxCare duplicates are dropped
• CVE-2026-3833 follow-up: the vendor's email_matches() no longer matches a bare-domain rfc822Name against a bare-domain constraint of the same length, which 3.3.29 did; restore that comparison, case-insensitively, and add the assertions to tests/name-constraints.c

• Rebased onto the vendor 3.3.29-9.0.3.el7_9 sources
• CVE-2026-5260: guard PKCS#11 RSA decryption against short-ciphertext heap overread (TuxCare fix retained)
• CVE-2026-42014 and CVE-2026-42015 are fixed by the vendor in this build
• CVE-2026-42011 is not applicable to this baseline per the vendor assessment
• CVE-2026-33845, CVE-2026-33846, CVE-2026-3833, CVE-2026-42009, CVE-2026-42012 and CVE-2026-42013 are now fixed by the vendor; the TuxCare duplicates are dropped
• CVE-2026-3833 follow-up: the vendor's email_matches() no longer matches a bare-domain rfc822Name against a bare-domain constraint of the same length, which 3.3.29 did; restore that comparison, case-insensitively, and add the assertions to tests/name-constraints.c

• CVE-2026-42011: a CA carrying only excluded name constraints, or permitted ones of another name type, no longer causes the permitted name constraints of a CA below it to be dropped during chain verification. This corrects the els1 entry: 3.3.29 is affected through the APPEND path of gnutls_x509_ext_import_name_constraints()

• CVE-2026-42011: a CA carrying only excluded name constraints, or permitted ones of another name type, no longer causes the permitted name constraints of a CA below it to be dropped during chain verification. This corrects the els1 entry: 3.3.29 is affected through the APPEND path of gnutls_x509_ext_import_name_constraints()

• CVE-2026-42011: a CA carrying only excluded name constraints, or permitted ones of another name type, no longer causes the permitted name constraints of a CA below it to be dropped during chain verification. This corrects the els1 entry: 3.3.29 is affected through the APPEND path of gnutls_x509_ext_import_name_constraints()

These are all security issues fixed in the gnutls-3.8.13-1.1 package on the GA media of openSUSE Tumbleweed.

This update for gnutls fixes the following issues

• CVE-2026-3832: cert-session: fix multi-entry OCSP revocation bypass (bsc#1263706).
• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

Root has patched CVE-2026-42011 in the rootio-gnutls28 package for Root:Debian:13. Multiple fixed versions available.

This update for gnutls fixes the following issues

• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3832: cert-session: fix multi-entry OCSP revocation bypass (bsc#1263706).
• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3832: cert-session: fix multi-entry OCSP revocation bypass (bsc#1263706).
• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3833: x509/name-constraints: compare domain names case-insensitive (bsc#1263707).
• CVE-2026-5260: lib/pkcs11_privkey: guard against overreading on short ciphertexts (bsc#1263715).
• CVE-2026-5419: gnutls_cipher_decrypt3: make PKCS#7 unpadding branch free (bsc#1263716).
• CVE-2026-33845: buffers: switch from end_offset over to frag_length (bsc#1263704).
• CVE-2026-33846: buffers: add more checks to DTLS reassembly (bsc#1263705).
• CVE-2026-42009: lib/buffers: ensure packets have differing sequence numbers (bsc#1263708).
• CVE-2026-42010: lib/auth/rsa_psk: fix binary PSK identity lookup (bsc#1263709).
• CVE-2026-42011: x509/name_constraints: fix intersecting empty constraints (bsc#1263710).
• CVE-2026-42012: x509/hostname-verify: make URI/SRV SAN preclude CN fallback (bsc#1263711).
• CVE-2026-42013: x509: prevent fallback on oversized SAN (bsc#1263712).
• CVE-2026-42014: pkcs11_write: fix UAF and leak in gnutls_pkcs11_token_set_pin (bsc#1263713).
• CVE-2026-42015: x509/pkcs12_bag: fix off-by-one in bag element bounds chec (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2025-14831: excessive resource consumption when verifying specially crafted malicious certificates containing a large number of name constraints and SANs (bsc#1257960).
• CVE-2026-3833: incorrectly accepted domain names due to comparison during name constraints processing being case-sensitive (bsc#1263707).
• CVE-2026-5260: heap overread when processing extremely short premaster secret as part of an RSA key exchange (bsc#1263715).
• CVE-2026-33845: integer overflow and heap overrun when parsing fragments with zero length and non-zero offset during DTLS handshake (bsc#1263704).
• CVE-2026-33846: heap overwrite during DTLS handshake fragment reassembly due to missing validations and checks (bsc#1263705).
• CVE-2026-42009: undefined behavior resulting in a DoS when handling DTLS packets with duplicate sequence numbers (bsc#1263708).
• CVE-2026-42010: authentication bypass when processing a PSK username with a NUL-character (bsc#1263709).
• CVE-2026-42011: name constraint bypass leading to acceptance of invalid certificates during certificate validation (bsc#1263710).
• CVE-2026-42012: spoofing of legitimate services and sensitive information interception via specially crafted certificates containing URIs or SRV SANs. (bsc#1263711).
• CVE-2026-42013: certificate validation bypass when validating certificates with an oversized SAN (bsc#1263712).
• CVE-2026-42014: use-after-free when an attacker attempts to change the PIN with a NULL old PIN for a token that lacks a protected authentication path (bsc#1263713).
• CVE-2026-42015: memory corruption when appending to a PKCS#12 bag that already contains 32 elements (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3833: incorrectly accepted domain names due to comparison during name constraints processing being case-sensitive (bsc#1263707).
• CVE-2026-5260: heap overread when processing extremely short premaster secret as part of an RSA key exchange (bsc#1263715).
• CVE-2026-42011: name constraint bypass leading to acceptance of invalid certificates during certificate validation (bsc#1263710).
• CVE-2026-42013: certificate validation bypass when validating certificates with an oversized SAN (bsc#1263712).
• CVE-2026-42014: use-after-free when an attacker attempts to change the PIN with a NULL old PIN for a token that lacks a protected authentication path (bsc#1263713).
• CVE-2026-42015: memory corruption when appending to a PKCS#12 bag that already contains 32 elements (bsc#1263714).

This update for gnutls fixes the following issues

• CVE-2026-3833: incorrectly accepted domain names due to comparison during name constraints processing being case-sensitive (bsc#1263707).
• CVE-2026-5260: heap overread when processing extremely short premaster secret as part of an RSA key exchange (bsc#1263715).
• CVE-2026-42011: name constraint bypass leading to acceptance of invalid certificates during certificate validation (bsc#1263710).
• CVE-2026-42013: certificate validation bypass when validating certificates with an oversized SAN (bsc#1263712).
• CVE-2026-42014: use-after-free when an attacker attempts to change the PIN with a NULL old PIN for a token that lacks a protected authentication path (bsc#1263713).
• CVE-2026-42015: memory corruption when appending to a PKCS#12 bag that already contains 32 elements (bsc#1263714).

Haruto Kimura discovered that GnuTLS did not properly apply permitted name constraints in certain certificate validation paths. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42011)

Oleh Konko discovered that GnuTLS incorrectly fell back to Common Name checks for certain URI and SRV subject alternative names. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42012)

Haruto Kimura and Joshua Rogers discovered that GnuTLS incorrectly fell back to Common Name checks when subject alternative names were oversized. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42013)

Luigino Camastra and Joshua Rogers discovered that GnuTLS had a use-after-free issue when changing PKCS#11 token security officer PINs in certain cases. An attacker could possibly use this issue to cause GnuTLS to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-42014)

Zou Dikai discovered that GnuTLS did not properly validate PKCS#12 bag sizes in certain cases. An attacker could possibly use this issue to cause GnuTLS to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-42015)