CVE-2026-91998

critical

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.

References

https://www.vulncheck.com/advisories/casdoor-through-4.4.0-cross-organization-user-administration-via-api-mcp

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/casdoor/casdoor/blob/v4.4.0/routers/base.go#L122-L154

https://github.com/casdoor/casdoor/blob/v4.4.0/mcpself/user.go

https://github.com/casdoor/casdoor/blob/v4.4.0/authz/authz.go#L174-L176

https://github.com/casdoor/casdoor

Details

Source: Mitre, NVD

Published: 2026-09-15

Updated: 2026-09-23

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 9.9

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

Severity: Critical

CVSS v4

Base Score: 9.4

Vector: 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

Severity: Critical

EPSS

EPSS: 0.00417