CVE-2026-42012 (GCVE-0-2026-42012)

Vulnerability from cvelistv5 – Published: 2026-05-26 21:29 – Updated: 2026-05-26 21:29
VLAI
Title
Gnutls: gnutls: certificate validation bypass due to improper handling of uri and srv sans
Summary
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 validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.
Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
CWE
  • CWE-295 - Improper Certificate Validation
Assigner
References
URL Tags
https://access.redhat.com/security/cve/CVE-2026-42012 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2467441 issue-trackingx_refsource_REDHAT
Impacted products
Date Public
2026-04-29 00:00
Credits
Red Hat would like to thank Oleh Konko (1Seal) for reporting this issue.
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.