CVE-2026-34457:
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.
Score
A numerical rating that indicates how dangerous this vulnerability is.
9.1Critical- Published Date:Apr 14, 2026
- CISA KEV Date:*No Data*
- Industries Affected:20
Exploitability
- Score:3.9
- Attack Vector:NETWORK
- Attack Complexity:LOW
- Privileges Required:NONE
- User Interaction:NONE
- Scope:UNCHANGED
Impact
- Score:5.2
- Confidentiality Impact:HIGH
- Integrity Impact:HIGH
- Availability Impact:NONE
Description Preview
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.
Industries Affected
Below is a list of industries most commonly impacted or potentially at risk based on intelligence.
