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CVE-2026-91998
Casdoor through 4.4.0 Cross-Organization User Administration via /api/mcp
Critical9.4EPSS 0.59%
- Published
- Updated
- Reserved
- Assigned by
- VulnCheck
Description
Casdoor through 4.4.0 contains an authorization bypass vulnerability in the /api/mcp endpoint that allows attackers with any application's clientId and clientSecret to gain unrestricted access to user administration across all organizations. Attackers can enumerate user records including password salts and email addresses, create administrator accounts, modify existing users, and delete them in any organization by supplying legitimate credentials from a single application.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | Critical9.4 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| VulnCheckCNA (assigner) | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Deferred | 4.0 | Critical9.4 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.59% · top 52% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.4.
Weakness
Affected products
References (6)
- Researcher write-up, Finding 2 (opens in a new tab)third-party-advisoryexploit
- authz/authz.go unconditional app allow at v4.4.0 (opens in a new tab)technical-description
- getUsernameByClientIdSecret at v4.4.0 (opens in a new tab)technical-description
- mcpself/user.go unscoped user tools at v4.4.0 (opens in a new tab)technical-description
- https://github.com/casdoor/casdoor (opens in a new tab)product
- VulnCheck Advisory: Casdoor through 4.4.0 Cross-Organization User Administration via /api/mcp (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-91998)Record last updated .