CVE-2026-42010

HIGH

Gnutls: gnutls: authentication bypass via nul character in username

Title source: cna
STIX 2.1

Description

A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.

References (3)

Core 3
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-42010
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2467289
https://bugzilla.redhat.com/show_bug.cgi?id=2467289
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:13274
https://access.redhat.com/errata/RHSA-2026:13274

Scores

CVSS v3 7.1
EPSS 0.0007
EPSS Percentile 21.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-626
Status published
Products (16)
gnu/gnutls
Red Hat/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/Red Hat Hardened Images
Red Hat/Red Hat Hardened Images 3.8.13-1.hum1
Red Hat/Red Hat OpenShift Container Platform 4
redhat/enterprise_linux 6.0
... and 6 more
Published May 07, 2026
Tracked Since May 07, 2026