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CVE-2026-42012

Gnutls: gnutls: certificate validation bypass due to improper handling of uri and srv sans

Published: May 26, 2026Updated: Jun 30, 2026 Sources: CVE List NVDCWE-295
7.1HIGH
NVD MITRE
EPSS Score
0.4%
Top 72.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

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

CWE-295

Affected Products

Red Hat
commercial·US
Red Hat Enterprise Linux 10On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 10.0 Extended Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsOn-premOS
Operating Systems / linux-distro
and 10 more affected products View all →

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
Scannable·OpenVAS
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://access.redhat.com/errata/RHSA-2026:20611
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20612
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20613
access.redhat.com
and 11 more references View all →
News mentions
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