---
title: "CVE-2026-91998: Casdoor - Authorization Bypass"
description: "Casdoor through 4.4.0 contains an authorization bypass caused by improper access control in the /api/mcp endpoint, letting attackers with any application's clientId and clientSecret gain unrestricted user administration access across all organizations, exploit requires valid clientId and clientSecret from any application."
url: https://panop.io/threat-heartbeat/CVE-2026-91998/
---

# CVE-2026-91998 Casdoor - Authorization Bypass

Casdoor through 4.4.0 contains an authorization bypass caused by improper access control in the /api/mcp endpoint, letting attackers with any application's clientId and clientSecret gain unrestricted user administration access across all organizations, exploit requires valid clientId and clientSecret from any application.

CVSS base score 9.9 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.59% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-91998)

## Details

Type

Authorization Bypass

Impact

Broken Access Control, Information Disclosure, Data Tampering

CVSS vector

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

Published

15 September 2026

Updated

15 October 2026

Weakness

[CWE-863](https://cwe.mitre.org/data/definitions/863.html)

## Vendor fix

Update to the latest version that fixes the authorization bypass vulnerability.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-91998](https://nvd.nist.gov/vuln/detail/CVE-2026-91998)
- [https://github.com/casdoor/casdoor](https://github.com/casdoor/casdoor)
- [https://github.com/casdoor/casdoor/blob/v4.4.0/authz/authz.go#L174-L176](https://github.com/casdoor/casdoor/blob/v4.4.0/authz/authz.go#L174-L176)
- [https://github.com/casdoor/casdoor/blob/v4.4.0/mcpself/user.go](https://github.com/casdoor/casdoor/blob/v4.4.0/mcpself/user.go)
- [https://github.com/casdoor/casdoor/blob/v4.4.0/routers/base.go#L122-L154](https://github.com/casdoor/casdoor/blob/v4.4.0/routers/base.go#L122-L154)
- [https://github.com/geo-chen/oss/blob/main/casdoor.md#finding-2-application-credential-authorization-bypass-in-apimcp-enables-unrestricted-cross-organization-user-administration](https://github.com/geo-chen/oss/blob/main/casdoor.md#finding-2-application-credential-authorization-bypass-in-apimcp-enables-unrestricted-cross-organization-user-administration)
- [https://www.vulncheck.com/advisories/casdoor-through-4.4.0-cross-organization-user-administration-via-api-mcp](https://www.vulncheck.com/advisories/casdoor-through-4.4.0-cross-organization-user-administration-via-api-mcp)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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