CVE-2026-42010

HIGH 7.1

Gnutls: gnutls: authentication bypass via nul character in username

CVSS Score

7.1

EPSS Score

1.1%

EPSS Percentile

63th

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.

CWE	CWE-170
Published	May 7, 2026
Last Updated	Sep 18, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

None

Affected Versions

Red Hat / Red Hat Enterprise Linux 10

All versions affected

Red Hat / Red Hat Enterprise Linux 10.0 Extended Update Support

All versions affected

Red Hat / Red Hat Enterprise Linux 8

All versions affected

Red Hat / Red Hat Enterprise Linux 8

All versions affected

Red Hat / Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

All versions affected

Red Hat / Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

All versions affected

Red Hat / Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

All versions affected

Red Hat / Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

All versions affected

Red Hat / Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

All versions affected

Red Hat / Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

All versions affected

Red Hat / Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

All versions affected

Red Hat / Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

All versions affected

Red Hat / Red Hat Enterprise Linux 8.8 Telecommunications Update Service

All versions affected

Red Hat / Red Hat Enterprise Linux 8.8 Telecommunications Update Service

All versions affected

Red Hat / Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

All versions affected

Red Hat / Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

All versions affected

Red Hat / Red Hat Enterprise Linux 9

All versions affected

Red Hat / Red Hat Enterprise Linux 9

All versions affected

Red Hat / Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

All versions affected

Red Hat / Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

All versions affected

Red Hat / Red Hat Enterprise Linux 9.6 Extended Update Support

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.12

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.13

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.14

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.16

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.17

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.18

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.19

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.20

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.21

All versions affected

Red Hat / Red Hat OpenShift Container Platform 4.22

All versions affected

Red Hat / Red Hat AI Inference Server 3.2

All versions affected

Red Hat / Red Hat AI Inference Server 3.2

All versions affected

Red Hat / Red Hat AI Inference Server 3.2

All versions affected

Red Hat / Red Hat Discovery 2

All versions affected

Red Hat / Red Hat Discovery 2

All versions affected

Red Hat / Red Hat Hardened Images

All versions affected