Summary
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.
Fixed packages 5
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux · 9 | gnutls | 3.8.10-4.el9_8 |
| AlmaLinux · 9 | gnutls-c++ | 3.8.10-4.el9_8 |
| AlmaLinux · 9 | gnutls-dane | 3.8.10-4.el9_8 |
| AlmaLinux · 9 | gnutls-devel | 3.8.10-4.el9_8 |
| AlmaLinux · 9 | gnutls-utils | 3.8.10-4.el9_8 |
Vulnerabilities 13
-
High 8.2
Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name
A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certi…
-
High 8.2
Gnutls: gnutls: information disclosure via heap overread in rsa key exchange
A flaw was found in libgnutls. A remote attacker, by sending an extremely short premaster secret during an RSA key exchange to a server using an RSA key backed by a PKCS#11 token, could trigger a short heap overread. This memory corruption vulnerability could…
-
High 7.5
Gnutls: gnutls: denial of service via dtls zero-length fragment
A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information dis…
-
High 7.5
Gnutls: gnutls: denial of service via heap buffer overflow in dtls handshake fragment reassembly
A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating th…
-
High 7.5
Gnutls: gnutls: denial of service via dtls packet reordering vulnerability
A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets …
-
High 7.4
Gnutls: gnutls: security bypass due to incorrect name constraint handling
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 cons…
-
High 7.1
Gnutls: gnutls: authentication bypass via nul character in username
A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username…
-
High 7.1
Gnutls: gnutls: certificate validation bypass due to improper handling of uri and srv sans
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate va…
-
Medium 6.6
Gnutls: gnutls: use-after-free in gnutls_pkcs11_token_set_pin
A flaw was found in GnuTLS. The `gnutls_pkcs11_token_set_pin` function, used for changing the Security Officer PIN, can lead to a use-after-free vulnerability. This occurs when an attacker attempts to change the PIN with a NULL old PIN for a token that lacks …
-
Medium 6.5
Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison
A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constraints within `excludedSubtrees` or `permittedSubtrees`. A remo…
-
Medium 5.3
Gnutls: gnutls: memory corruption due to off-by-one error in pkcs#12 bag handling
A flaw was found in gnutls. An off-by-one error exists in the PKCS#12 bag element bounds check. This vulnerability allows an remote attacker to write past the internal array of a PKCS#12 bag when appending to a bag that already contains 32 elements. This memo…
-
Low 3.7
Gnutls: gnutls: security bypass allows acceptance of revoked server certificates via crafted ocsp response
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted Online Certificate Status Protocol (OCSP) response during a TLS handshake. Due to a logic error in how gnutls processes multi-record OCSP response…
-
Low 3.7
Gnutls: gnutls: information disclosure via timing side-channel in pkcs#7 padding removal
A flaw was found in gnutls. The PKCS#7 padding check, performed during decryption, was not constant-time. This timing side-channel could allow a remote attacker to potentially leak sensitive information about the padding bytes through observable timing differ…
References
-
report
https://access.redhat.com/security/cve/CVE-2026-33845
-
report
https://access.redhat.com/security/cve/CVE-2026-33846
-
report
https://access.redhat.com/security/cve/CVE-2026-3832
-
report
https://access.redhat.com/security/cve/CVE-2026-3833
-
report
https://access.redhat.com/security/cve/CVE-2026-42009
-
report
https://access.redhat.com/security/cve/CVE-2026-42010
-
report
https://access.redhat.com/security/cve/CVE-2026-42011
-
report
https://access.redhat.com/security/cve/CVE-2026-42012
-
report
https://access.redhat.com/security/cve/CVE-2026-42013
-
report
https://access.redhat.com/security/cve/CVE-2026-42014
-
report
https://access.redhat.com/security/cve/CVE-2026-42015
-
report
https://access.redhat.com/security/cve/CVE-2026-5260
-
report
https://access.redhat.com/security/cve/CVE-2026-5419
-
report
https://bugzilla.redhat.com/2445763
-
report
https://bugzilla.redhat.com/2450624
-
report
https://bugzilla.redhat.com/2450625
-
report
https://bugzilla.redhat.com/2467279
-
report
https://bugzilla.redhat.com/2467289
-
report
https://bugzilla.redhat.com/2467437
-
advisory
https://errata.almalinux.org/9/ALSA-2026-20612.html