{"cve":"CVE-2026-34457","nvd":{"published":"2026-04-14T23:16:28.330","modified":"2026-07-24T22:10:00.140","status":"Analyzed","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-290"],"references":["https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2","https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5hvv-m4w4-gf6v"],"products":["oauth2_proxy_project:oauth2_proxy"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-34457","score":0.00475,"percentile":0.4106,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5hvv-m4w4-gf6v","url":"https://osv.dev/vulnerability/GHSA-5hvv-m4w4-gf6v","summary":" OAuth2 Proxy's Health Check User-Agent Matching Bypasses Authentication in auth_request Mode","modified":"2026-06-25T18:56:29.674113323Z","packages":[{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy/v7","purl":"pkg:golang/github.com/oauth2-proxy/oauth2-proxy/v7","ranges":["<7.15.2"],"fixed":["7.15.2"]},{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy","purl":"pkg:golang/github.com/oauth2-proxy/oauth2-proxy","ranges":["<=3.2.0"],"fixed":[]}]},{"id":"GO-2026-5147","url":"https://osv.dev/vulnerability/GO-2026-5147","summary":"OAuth2 Proxy's Health Check User-Agent Matching Bypasses Authentication in auth_request Mode in github.com/oauth2-proxy/oauth2-proxy","modified":"2026-06-25T18:56:29.674113323Z","packages":[{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy","purl":"pkg:golang/github.com/oauth2-proxy/oauth2-proxy","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy/v7","purl":"pkg:golang/github.com/oauth2-proxy/oauth2-proxy/v7","ranges":["<7.15.2"],"fixed":["7.15.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}