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CVE-2026-42013

Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name

Published: May 26, 2026Updated: May 26, 2026 Sources: CVE List NVD
NVD MITRE
8.2CVSS
HIGH

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 certificate validation, potentially leading to spoofing or man-in-the-middle attacks.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:HIntegrity
High
A:NAvailability
None

Weaknesses

CWE-1284

Affected Products

Red Hat Enterprise Linux 10
Red Hat
Red Hat Enterprise Linux 6
Red Hat
Red Hat Enterprise Linux 7
Red Hat
Red Hat Enterprise Linux 8
Red Hat
Red Hat Enterprise Linux 9
Red Hat
and 2 more affected products View all →

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://access.redhat.com/security/cve/CVE-2026-42013
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2467448
bugzilla.redhat.com

Timeline

Published
May 26, 2026
Last Updated
May 26, 2026

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