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.
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 26 Oct 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Nosduco
Nosduco nforwardauth |
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| Vendors & Products |
Nosduco
Nosduco nforwardauth |
Mon, 26 Oct 2026 18:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | Unvalidated r parameter allows post-authentication open redirect | nforwardauth: Unvalidated r parameter allows post-authentication open redirect |
Mon, 26 Oct 2026 17:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Unvalidated r parameter allows post-authentication open redirect | |
| Weaknesses | CWE-601 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-10-26T19:34:58.155Z
Reserved: 2026-08-26T20:58:58.084Z
Link: CVE-2026-81509
No data.
Status : Deferred
Published: 2026-10-26T18:18:46.367
Modified: 2026-10-26T20:18:37.683
Link: CVE-2026-81509
No data.
OpenCVE Enrichment
Updated: 2026-10-26T19:09:04Z
Weaknesses