CVE-2026-42013
Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name
CVSS 3.1 8.2 HIGHCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-42013
PublishedA 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 certificate validation, potentially leading to spoofing or man-in-the-middle attacks.
Read the publisher's advisoryAffected versions, risk and source history
Related advisories and sources
Publishers link these advisories through the identifiers shown below. A shared identifier or date alone does not tell you whether your software is affected or whether the advisories describe the same cause.
CVE-2026-42013 · CVE overview and exploitation status
cve-program · CVE-2026-42013
- https://access.redhat.com/errata/RHSA-2026:13274
- https://access.redhat.com/errata/RHSA-2026:20611
- https://access.redhat.com/errata/RHSA-2026:20612
- https://access.redhat.com/errata/RHSA-2026:20613
- https://access.redhat.com/errata/RHSA-2026:26319
- https://access.redhat.com/errata/RHSA-2026:26409
- https://access.redhat.com/errata/RHSA-2026:29197
- https://access.redhat.com/errata/RHSA-2026:30004
- https://access.redhat.com/errata/RHSA-2026:30849
- https://access.redhat.com/errata/RHSA-2026:30850
- https://access.redhat.com/errata/RHSA-2026:32962
- https://access.redhat.com/errata/RHSA-2026:33125
- https://access.redhat.com/errata/RHSA-2026:40762
- https://access.redhat.com/errata/RHSA-2026:41921
- https://access.redhat.com/errata/RHSA-2026:43575
- https://access.redhat.com/errata/RHSA-2026:56853
- https://access.redhat.com/errata/RHSA-2026:57483
- https://access.redhat.com/errata/RHSA-2026:58981
- https://access.redhat.com/errata/RHSA-2026:59831
- https://access.redhat.com/errata/RHSA-2026:60019
- https://access.redhat.com/errata/RHSA-2026:72502
- https://access.redhat.com/errata/RHSA-2026:74674
- https://access.redhat.com/errata/RHSA-2026:82304
- https://access.redhat.com/errata/RHSA-2026:82322
- https://access.redhat.com/errata/RHSA-2026:82347
- https://access.redhat.com/errata/RHSA-2026:82354
- https://access.redhat.com/errata/RHSA-2026:82372
- https://access.redhat.com/errata/RHSA-2026:82857
- https://access.redhat.com/errata/RHSA-2026:82888
- https://access.redhat.com/errata/RHSA-2026:89197
- https://access.redhat.com/errata/RHSA-2026:89232
- https://access.redhat.com/errata/RHSA-2026:89333
- https://access.redhat.com/errata/RHSA-2026:95508
- https://access.redhat.com/errata/RHSA-2026:95745
- https://access.redhat.com/errata/RHSA-2026:95755
- https://access.redhat.com/security/cve/CVE-2026-42013
- https://bugzilla.redhat.com/show_bug.cgi?id=2467448
- https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-8
Related changes
Linked by CVE identifier- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 11 Nov 2026
- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 11 Nov 2026
- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 9 Nov 2026
- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 5 Nov 2026
- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 30 Oct 2026
- Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name · Affected-version evidence changed · 29 Oct 2026