RHSA-2026:20613 - Security Advisory

Topic

An update for gnutls is now available for Red Hat Enterprise Linux 10.

Red Hat Product Security has rated this update as having a security impact of
Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a
detailed severity rating, is available for each vulnerability from the CVE
link(s) in the References section.

Description

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.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 10 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x

Fixes

• BZ - 2445763 - CVE-2026-3833 gnutls: GnuTLS: Policy bypass due to case-sensitive nameConstraints comparison
• BZ - 2450624 - CVE-2026-33845 gnutls: GnuTLS: Denial of Service via DTLS zero-length fragment
• BZ - 2450625 - CVE-2026-33846 gnutls: GnuTLS: Denial of Service via heap buffer overflow in DTLS handshake fragment reassembly
• BZ - 2467279 - CVE-2026-42009 gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability
• BZ - 2467289 - CVE-2026-42010 gnutls: gnutls: Authentication Bypass via NUL Character in Username
• BZ - 2467437 - CVE-2026-42011 gnutls: gnutls: Security bypass due to incorrect name constraint handling

CVEs

• CVE-2026-3832
• CVE-2026-3833
• CVE-2026-5260
• CVE-2026-5419
• CVE-2026-33845
• CVE-2026-33846
• CVE-2026-42009
• CVE-2026-42010
• CVE-2026-42011
• CVE-2026-42012
• CVE-2026-42013
• CVE-2026-42014
• CVE-2026-42015

References

• https://access.redhat.com/security/updates/classification/#important