CVE-2026-91998

Casdoor through 4.4.0 Cross-Organization User Administration via /api/mcp

CRITICAL
9.9
CVSS Score
Published: September 15, 2026 at 11:35 AM UTC
Updated: September 23, 2026 at 05:30 PM UTC
2 products affected across 2 vendorsCasdoorCasdoor

Using casdoor by casdoor?

Get instant alerts when new vulnerabilities affect casdoor - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
CRITICAL9.9
Exploit prediction
EPSS 0.6%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 4.4.0
v ≤ 4.4.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

9.9CRITICALVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-863

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card