Payload CMS MCP Plugin Improper Access Control Vulnerability

An authenticated user could manage MCP API keys outside their intended account in Payload CMS plugin-mcp, allowing privilege escalation through account takeover. The vulnerability was patched in version 3.88.0.

Disclosed 6 October 2026 · Record updated 6 October 2026

Impact

Authenticated users could escalate privileges through improper access control to MCP API keys, potentially leading to account takeover

Our coverage

A locksmith's ring of master keys hangs vulnerable on a wall as unauthorized hands reach past the guard, selecting any key they need before the lock resets.

Vulnerabilities

Payload patches MCP plugin flaw that allowed account takeover

An advisory published on 6 October 2026 says authenticated users could manage MCP API keys belonging to other accounts until version 3.88.0.

6 Oct 2026

Sources

github.comhttps://github.com/advisories/GHSA-2q76-m6w6-qgc6