CVE-2026-42010
Gnutls: gnutls: authentication bypass via nul character in username
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.
INFO
Published Date :
May 7, 2026, 12:16 p.m.
Last Modified :
May 27, 2026, 4:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-42010
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update GnuTLS to the latest version.
- Verify server RSA-PSK configuration.
- Disable RSA-PSK if not necessary.
Public PoC/Exploit Available at Github
CVE-2026-42010 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42010.
| URL | Resource |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:13274 | |
| https://access.redhat.com/errata/RHSA-2026:20611 | |
| https://access.redhat.com/security/cve/CVE-2026-42010 | Vendor Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2467289 | Issue Tracking Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42010 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42010
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Python Dockerfile
Enterprise AWS Zero Trust Architecture with ECS Fargate, WAF, KMS, GuardDuty, Security Hub, and CloudTrail.
Dockerfile HTML Shell
None
Dockerfile Makefile Shell Python
None
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42010 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42010 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 27, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:20611 -
CVE Modified by [email protected]
May. 14, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:13274 -
Initial Analysis by [email protected]
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* *cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-42010 Types: Vendor Advisory Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2467289 Types: Issue Tracking, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 07, 2026
Action Type Old Value New Value Added CWE CWE-626 -
New CVE Received by [email protected]
May. 07, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N Added Reference https://access.redhat.com/security/cve/CVE-2026-42010 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2467289