Description
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.
Published: 2026-05-26
Score: 8.2 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4595-1 gnutls28 security update
Debian DSA Debian DSA DSA-6281-1 gnutls28 security update
Ubuntu USN Ubuntu USN USN-8284-1 GnuTLS vulnerabilities
History

Mon, 29 Jun 2026 12:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:rhel_e4s:9.4::appstream
cpe:/o:redhat:rhel_e4s:9.4::baseos
References

Mon, 29 Jun 2026 08:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus Long Life
Redhat rhel Tus
CPEs cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_eus_long_life:8.6::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
cpe:/o:redhat:rhel_aus:8.6::baseos
cpe:/o:redhat:rhel_e4s:8.8::baseos
cpe:/o:redhat:rhel_eus_long_life:8.6::baseos
cpe:/o:redhat:rhel_tus:8.8::baseos
Vendors & Products Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus Long Life
Redhat rhel Tus
References

Fri, 26 Jun 2026 07:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.6::appstream
cpe:/o:redhat:rhel_eus:9.6::baseos
Vendors & Products Redhat rhel Eus
References

Thu, 25 Jun 2026 23:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-295
References

Wed, 24 Jun 2026 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Redhat discovery
CPEs cpe:/a:redhat:discovery:2::el9
Vendors & Products Redhat discovery
References

Tue, 16 Jun 2026 22:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat enterprise Linux Eus
Redhat rhui
CPEs cpe:/a:redhat:rhui:5::el9
cpe:/o:redhat:enterprise_linux_eus:10.0
Vendors & Products Redhat enterprise Linux Eus
Redhat rhui
References

Tue, 02 Jun 2026 15:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:9 cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/o:redhat:enterprise_linux:9::baseos
References

Mon, 01 Jun 2026 20:30:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:10.2
References

Thu, 28 May 2026 22:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 27 May 2026 10:30:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu gnutls
Redhat hardened Images
Redhat openshift Container Platform
Vendors & Products Gnu
Gnu gnutls
Redhat hardened Images
Redhat openshift Container Platform

Wed, 27 May 2026 03:30:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:8 cpe:/a:redhat:enterprise_linux:8::appstream
cpe:/o:redhat:enterprise_linux:8::baseos
References

Tue, 26 May 2026 21:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat openshift
Weaknesses CWE-1284
CPEs cpe:/a:redhat:hummingbird:1
cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat openshift
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N'}


Subscriptions

Gnu Gnutls
Redhat Discovery Enterprise Linux Enterprise Linux Eus Hardened Images Hummingbird Openshift Openshift Container Platform Rhel Aus Rhel E4s Rhel Eus Rhel Eus Long Life Rhel Tus Rhui
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-06-29T10:18:31.538Z

Reserved: 2026-04-23T11:23:46.517Z

Link: CVE-2026-42013

cve-icon Vulnrichment

Updated: 2026-05-28T14:13:54.446Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-26T22:16:42.050

Modified: 2026-06-17T13:20:39.300

Link: CVE-2026-42013

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-26T01:00:06Z

Weaknesses