CVE-2026-34457 (GCVE-0-2026-34457)

Vulnerability from cvelistv5 – Published: 2026-04-14 22:14 – Updated: 2026-04-15 17:43
VLAI
Title
OAuth2 Proxy: Health Check User-Agent Matching Bypasses Authentication in auth_request Mode
Summary
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.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-15 17:43 UTC
CWE
  • CWE-290 - Authentication Bypass by Spoofing
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7658 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
oauth2-proxy oauth2-proxy Affected: < 7.15.2
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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