Vulnerability Description
OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions prior to 7.15.2 contain a configuration-dependent authentication bypass in deployments where OAuth2 Proxy is used with an auth_request-style integration (such as nginx auth_request) and either --ping-user-agent is set or --gcp-healthchecks is enabled. In affected configurations, OAuth2 Proxy treats any request with the configured health check User-Agent value as a successful health check regardless of the requested path, allowing an unauthenticated remote attacker to bypass authentication and access protected upstream resources. Deployments that do not use auth_request-style subrequests or that do not enable --ping-user-agent/--gcp-healthchecks are not affected. This issue is fixed in 7.15.2.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Oauth2 Proxy Project | Oauth2 Proxy | < 7.15.2 |
Related Weaknesses (CWE)
References
- https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2Release Notes
- https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5hvv-m4w4-Vendor AdvisoryMitigation
FAQ
What is CVE-2026-34457?
CVE-2026-34457 is a vulnerability with a CVSS score of 9.1 (CRITICAL). OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions prior to 7.15.2 contain a configuration-dependent authentication bypass in deployments where OAuth2 Proxy ...
How severe is CVE-2026-34457?
CVE-2026-34457 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-34457?
Check the references section above for vendor advisories and patch information. Affected products include: Oauth2 Proxy Project Oauth2 Proxy.