Casdoor SAML callback handler accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-9098: 0.23% estimated exploitation activity in the next 30 days; percentile 13.96 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

In Casdoor versions 2.362.0 and earlier, the SAML callback handler in controllers/auth.go accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest previously issued by Casdoor. Additionally, if an administrator disables or deletes an IdP (Identity Provider) after a SAML flow has started, the handler still processes the response using the provider snapshot loaded at the start of the request. As a result, an attacker controlling a registered upstream IdP can send unsolicited SAML responses, or replay a legitimately captured response in a different session or after the original flow has ended. In both cases, Casdoor accepts the response and issues a session, enabling persistent unauthorized access.

Published by the source

28 May 2026, 18:30 UTC

Last modified by the source

2 Jul 2026, 18:38 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mfvp-7p3v-x9mh

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# Patch Next advisory brief: CVE-2026-9098

Advisory: Casdoor SAML callback handler accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest
IDs: CVE-2026-9098, GHSA-mfvp-7p3v-x9mh
Record: https://patchnext.com/advisories/cve-2026-9098 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/casdoor/casdoor: affected <= 1.1000.1-0.20260321120606-239e8bd69487

## Suggested inspection (read-only)
- Go github.com/casdoor/casdoor: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/casdoor/casdoor.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-mfvp-7p3v-x9mh (GitHub-reviewed advisory GHSA-mfvp-7p3v-x9mh lists affected ranges: Go github.com/casdoor/casdoor >=0 <=1.1000.1-0.20260321120606-239e8bd69487)

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