CVE-2026-25651: client-certificate-auth Vulnerable to Open Redirect via Host Header Injection in HTTP-to-HTTPS redirect

February 6, 2026

Versions 0.2.1 and 0.3.0 of client-certificate-auth contain an open redirect vulnerability. The middleware unconditionally redirects HTTP requests to HTTPS using the unvalidated Host header, allowing an attacker to redirect users to arbitrary domains.

References

github.com/advisories/GHSA-m4w9-gch5-c2g4
github.com/tgies/client-certificate-auth
github.com/tgies/client-certificate-auth/commit/8fc995e953db483495be46862965e50fe9e1cc52
github.com/tgies/client-certificate-auth/security/advisories/GHSA-m4w9-gch5-c2g4
nvd.nist.gov/vuln/detail/CVE-2026-25651

Code Behaviors & Features

Detect and mitigate CVE-2026-25651 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →