Vulnerability · Published May 7, 2026 · Assigned by redhat
CVE-2026-42011Gnutls: gnutls: security bypass due to incorrect name constraint handling
High 7.4
In plain English
A high-severity improper certificate validation in gnutls. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | gnutls | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:8 | gnutls | 3.6.16-8.el8_10.6 | ALSA-2026:20611 |
| AlmaLinux:9 | gnutls | 3.8.10-4.el9_8 | ALSA-2026:20612 |
| AlmaLinux:10 | gnutls-c++ | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:8 | gnutls-c++ | 3.6.16-8.el8_10.6 | ALSA-2026:20611 |
| AlmaLinux:9 | gnutls-c++ | 3.8.10-4.el9_8 | ALSA-2026:20612 |
| AlmaLinux:10 | gnutls-dane | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:8 | gnutls-dane | 3.6.16-8.el8_10.6 | ALSA-2026:20611 |
| AlmaLinux:9 | gnutls-dane | 3.8.10-4.el9_8 | ALSA-2026:20612 |
| AlmaLinux:10 | gnutls-devel | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:8 | gnutls-devel | 3.6.16-8.el8_10.6 | ALSA-2026:20611 |
| AlmaLinux:9 | gnutls-devel | 3.8.10-4.el9_8 | ALSA-2026:20612 |
| AlmaLinux:10 | gnutls-fips | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:10 | gnutls-utils | 3.8.10-4.el10_2 | ALSA-2026:20613 |
| AlmaLinux:8 | gnutls-utils | 3.6.16-8.el8_10.6 | ALSA-2026:20611 |
| AlmaLinux:9 | gnutls-utils | 3.8.10-4.el9_8 | ALSA-2026:20612 |
| Alpine:v3.20 | gnutls | 3.8.13-r0 | ALPINE-CVE-2026-42011 |
| Alpine:v3.21 | gnutls | 3.8.13-r0 | ALPINE-CVE-2026-42011 |
| Alpine:v3.22 | gnutls | 3.8.13-r0 | ALPINE-CVE-2026-42011 |
| Alpine:v3.23 | gnutls | 3.8.13-r0 | ALPINE-CVE-2026-42011 |
| Alpine:v3.24 | gnutls | 3.8.13-r0 | ALPINE-CVE-2026-42011 |
| Debian:12 | gnutls28 | 3.7.9-2+deb12u7 | DEBIAN-CVE-2026-42011 |
| Debian:13 | gnutls28 | 3.8.9-3+deb13u4 | DEBIAN-CVE-2026-42011 |
| Debian:14 | gnutls28 | 3.8.13-1 | DEBIAN-CVE-2026-42011 |
| Rocky Linux:10 | gnutls | 0:3.8.10-4.el10_2 | RLSA-2026:20613 |
| Rocky Linux:8 | gnutls | 0:3.6.16-8.el8_10.6 | RLSA-2026:20611 |
| Rocky Linux:9 | gnutls | 0:3.8.10-4.el9_8 | RLSA-2026:20612 |
| Ubuntu:22.04:LTS | gnutls28 | 3.7.3-4ubuntu1.9 | UBUNTU-CVE-2026-42011 |
| Ubuntu:24.04:LTS | gnutls28 | 3.8.3-1.1ubuntu3.6 | UBUNTU-CVE-2026-42011 |
| Ubuntu:25.10 | gnutls28 | 3.8.9-3ubuntu2.2 | UBUNTU-CVE-2026-42011 |
| Ubuntu:26.04:LTS | gnutls28 | 3.8.12-2ubuntu1.1 | UBUNTU-CVE-2026-42011 |
Affected products (as reported)
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- RHSA-2026:13274 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:20611 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:20612 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:20613 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:26319 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:26409 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:29197 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:30004 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:30849 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:30850 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:32962 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:33125 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:40762 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:41921 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:43575 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:56853 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:57483 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:58981 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59831 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:60019 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:72502 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:74674 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82304 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82322 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82347 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82354 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82372 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82857 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:82888 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:89197 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:89232 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:89333 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-42011 vdb-entry, x_refsource_REDHAT
- RHBZ#2467437 issue-tracking, x_refsource_REDHAT
- https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-6