{"cve":"CVE-2020-4037","nvd":{"published":"2020-06-29T20:15:10.317","modified":"2026-06-17T03:19:27.737","status":"Modified","description":"In OAuth2 Proxy from version 5.1.1 and less than version 6.0.0, users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites. This has been fixed in version 6.0.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","score":5.4},"cwes":["CWE-601"],"references":["https://github.com/oauth2-proxy/oauth2-proxy/commit/ee5662e0f5001d76ec76562bb605abbd07c266a2","https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5m6c-jp6f-2vcv","https://github.com/oauth2-proxy/oauth2-proxy/commit/ee5662e0f5001d76ec76562bb605abbd07c266a2","https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5m6c-jp6f-2vcv"],"products":["oauth2_proxy_project:oauth2_proxy"],"source":"nvd","synced_at":"2026-10-19T21:06:22.076270124+00:00"},"epss":{"cve":"CVE-2020-4037","score":0.00896,"percentile":0.59558,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5m6c-jp6f-2vcv","url":"https://osv.dev/vulnerability/GHSA-5m6c-jp6f-2vcv","summary":"Open Redirect in OAuth2 Proxy","modified":"2026-07-08T06:28:51.722548859Z","packages":[{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy","purl":"pkg:golang/github.com/oauth2-proxy/oauth2-proxy","ranges":[">=5.1.1 <6.0.0"],"fixed":["6.0.0"]}]}],"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."]}