CVE-2026-42010
Gnutls: gnutls: authentication bypass via nul character in username
7.1CVSSHIGH
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.
CVSS Vector Breakdown
Exploitability
AV:NAttack VectorNetwork
AC:LAttack ComplexityLow
PR:LPrivileges RequiredLow
UI:NUser InteractionNone
Scope
S:UScopeUnchanged
Impact
C:HConfidentialityHigh
I:LIntegrityLow
A:NAvailabilityNone
Weaknesses
Affected Products
and 8 more affected products View all →
Exploitability
Official Patch Available
References
https://access.redhat.com/errata/RHSA-2026:13274
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20611
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20612
access.redhat.com
and 5 more references View all →
Timeline
Published
May 7, 2026
Last Updated
Jun 17, 2026
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