---
id: CVE-2026-91998
title: >-
  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
  organizati…
summary: >-
  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
  organizati…
severity: critical
cvss: 9.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-863
vendor: casdoor
product: casdoor
affected:
  - casdoor <= 4.4.0
published: '2026-09-15'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T20:18:55.133'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91998'
references:
  - url: 'https://github.com/casdoor/casdoor'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/casdoor/casdoor/blob/v4.4.0/authz/authz.go#L174-L176'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/casdoor/casdoor/blob/v4.4.0/mcpself/user.go'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/casdoor/casdoor/blob/v4.4.0/routers/base.go#L122-L154'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/geo-chen/oss/blob/main/casdoor.md#finding-2-application-credential-authorization-bypass-in-apimcp-enables-unrestricted-cross-organization-user-administration
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/casdoor-through-4.4.0-cross-organization-user-administration-via-api-mcp
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-17T18:38:32.655911Z'
epss: 0.00417
epssPercentile: 0.35698
ingestedAt: '2026-09-15T12:36:50.174Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.