CVE-2026-42010 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for Red Hat Enterprise Linux systems and gnutls configurations should assess exposure and apply patches or updates to prevent exploitation.

Why it matters

CVE-2026-42010 is an authentication bypass vulnerability in gnutls that affects Red Hat Enterprise Linux systems configured with RSA-PSK. System administrators and security teams should assess exposure, apply patches or updates, and monitor systems for suspicious activity.

• Potential unauthorized access to sensitive systems and data.
• Bypass of authentication mechanisms, leading to increased risk of system compromise.
• Need for verification of current gnutls configurations and versions.
• Priority for applying patches or updates to fix the vulnerability.

Technical summary

The gnutls library has a flaw that allows for authentication bypass via specially crafted usernames containing NUL characters. This affects servers configured with RSA-PSK. An attacker could exploit this by sending a specially crafted username, leading to unauthorized access. The vulnerability is particularly concerning for Red Hat Enterprise Linux systems, which may be exposed if not properly patched. System administrators should review gnutls configurations and apply updates to prevent exploitation. The vulnerability highlights the importance of robust username validation and secure configuration practices.

Defensive priority

Apply patches or updates from gnutls and Red Hat to fix the authentication bypass vulnerability.

Recommended defensive actions

• Apply patches or updates from gnutls and Red Hat to fix the authentication bypass vulnerability.
• Review and update RSA-PSK configurations to prevent exploitation.
• Monitor systems for suspicious authentication attempts.
• Verify current gnutls configurations and versions.
• Assess exposure and prioritize patching for Red Hat Enterprise Linux systems.
• Implement compensating controls for exposed systems while remediation is scheduled.
• Track exceptions and retest remediated assets.

Evidence notes

The CVE record and NVD detail page provide information on the vulnerability, while Red Hat errata advisories offer patches and updates. Additional evidence from gnutls documentation and security advisories confirms the vulnerability's impact on RSA-PSK configurations. Further verification is needed to assess the vulnerability's scope and apply necessary patches or updates.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.