ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-42010

Gnutls: gnutls: authentication bypass via nul character in username

Published May 7, 2026 · catalog updated Oct 14, 2026 · Gnutls: gnutls: authentication bypass

Check if you run it

No confirmed exploitation is on record for CVE-2026-42010. EPSS is 0.94%. Act only if a listed version of Gnutls: gnutls: authentication bypass is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Gnutls: gnutls: authentication bypass).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.94%
Remediation
Not established
Affected products
cpe gnu/gnutls · cpe redhat/enterprise linux · cpe redhat/hardened images · cpe redhat/openshift container platform · vendor Red Hat Red Hat Enterprise Linux 10 · vendor Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe gnu/gnutlsversion unspecified
  • cpe redhat/enterprise linux10.0
  • cpe redhat/enterprise linux6.0
  • cpe redhat/enterprise linux7.0
  • cpe redhat/enterprise linux8.0
  • cpe redhat/enterprise linux9.0
  • cpe redhat/hardened imagesversion unspecified
  • cpe redhat/openshift container platform4.0
  • vendor Red Hat Red Hat Enterprise Linux 10version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 10.0 Extended Update Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onversion unspecified

How to fix CVE-2026-42010

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-42010. EPSS is 0.94%. Act only if a listed version of Gnutls: gnutls: authentication bypass is installed.

Which versions are affected?

Compare what you have installed with redhat/enterprise linux 10.0; redhat/enterprise linux 6.0; redhat/enterprise linux 7.0; redhat/enterprise linux 8.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-170; CWE-626. EPSS 0.94%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 7, 2026 · Catalog

    Detected

    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

  2. Oct 14, 2026 · Catalog

    Updated

    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

  3. Oct 14, 2026 · NIST NVD

    Updated

    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

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-2026-42010

    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 authe

    vulnerability.circl.lu
  • CVE.orgVulnerability recordCVE-2026-42010

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-42010

    30-day exploitation probability 0.9%

    first.org
  • NIST NVDVulnerability recordCVE-2026-42010

    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 authe

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.