{"schema":"threatline.record/2","record":{"id":"CVE-2026-81509","aliases":["GHSA-q64r-v7j5-6hfg"],"summary":"nforwardauth: Unvalidated r parameter allows post-authentication open redirect","details":"nforwardauth is a forward auth service that allows the use of a single authentication middleware for multiple sites. Versions prior to 1.5.1 accept an unvalidated `r` query parameter on the `/login` endpoint and use them as the post-authentication redirect destination. An unauthenticated attacker can create a legitimate `nforwardauth` login URL that redirects a victim to an attacker-controlled website after the victim successfully authenticates. This issue may facilitate phishing and other social-engineering attacks by abusing the trust associated with the legitimate authentication domain. This vulnerability does not provide an unauthenticated ForwardAuth bypass. Version 1.5.1 contains a patch.","categories":["Unclassified"],"product":"nforwardauth","vendor":"nosduco","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-81509","source_modified_at":"2026-10-26T18:12:30.433Z","fetched_at":"2026-10-26T19:10:57.178988Z","product":"nforwardauth","vendor":"nosduco","versions":[{"version":"< 1.5.1","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":6.1,"severity":"Medium","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-26T17:19:15.467Z","modified_at":"2026-10-26T18:12:30.433Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-81509","fetched_at":"2026-10-26T19:10:57.178988Z","source_modified_at":"2026-10-26T18:12:30.433Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://github.com/nosduco/nforwardauth/security/advisories/GHSA-q64r-v7j5-6hfg","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/nosduco/nforwardauth/pull/71","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/nosduco/nforwardauth/commit/664f2602f9e1459558d1c4c55019f6d48bc64c43","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/nosduco/nforwardauth/releases/tag/v1.5.1","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-26T18:12:30.433Z","content_hash":"e906abf5bb58bc784baadf01f782dc861ed07c54d9fdfb1cc765597d87890e36"}}