CVE-2026-34457

9.1 CRITICAL
Published: April 14, 2026 Modified: April 23, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2
Source: security-advisories@github.com
Release Notes
https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5hvv-m4w4-gf6v
Source: security-advisories@github.com
Vendor Advisory Mitigation

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.1 / 10.0
EPSS (Exploit Probability)
0.1%
27th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

oauth2_proxy_project