{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-81509", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-26T20:58:58.084Z", "datePublished": "2026-10-26T17:19:15.467Z", "dateUpdated": "2026-10-26T18:12:30.433Z"}, "containers": {"cna": {"title": "nforwardauth: Unvalidated r parameter allows post-authentication open redirect", "problemTypes": [{"descriptions": [{"cweId": "CWE-601", "lang": "en", "description": "CWE-601: URL Redirection to Untrusted Site ('Open Redirect')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/nosduco/nforwardauth/security/advisories/GHSA-q64r-v7j5-6hfg", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/nosduco/nforwardauth/security/advisories/GHSA-q64r-v7j5-6hfg"}, {"name": "https://github.com/nosduco/nforwardauth/pull/71", "tags": ["x_refsource_MISC"], "url": "https://github.com/nosduco/nforwardauth/pull/71"}, {"name": "https://github.com/nosduco/nforwardauth/commit/664f2602f9e1459558d1c4c55019f6d48bc64c43", "tags": ["x_refsource_MISC"], "url": "https://github.com/nosduco/nforwardauth/commit/664f2602f9e1459558d1c4c55019f6d48bc64c43"}, {"name": "https://github.com/nosduco/nforwardauth/releases/tag/v1.5.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/nosduco/nforwardauth/releases/tag/v1.5.1"}], "affected": [{"vendor": "nosduco", "product": "nforwardauth", "versions": [{"version": "< 1.5.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-26T18:12:30.433Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-q64r-v7j5-6hfg", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "nforwardauth", "vendor": "nosduco", "versions": [{"status": "affected", "version": "< 1.5.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-81509", "lastModified": "2026-10-26T18:41:21.450", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-26T18:18:46.367", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/nosduco/nforwardauth/commit/664f2602f9e1459558d1c4c55019f6d48bc64c43"}, {"source": "security-advisories@github.com", "url": "https://github.com/nosduco/nforwardauth/pull/71"}, {"source": "security-advisories@github.com", "url": "https://github.com/nosduco/nforwardauth/releases/tag/v1.5.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/nosduco/nforwardauth/security/advisories/GHSA-q64r-v7j5-6hfg"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-601"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}