In Percona Monitoring and Management (PMM) server 2.x before 2.37.1, the authenticate function in auth_server.go does not properly formalize and sanitize URL paths to reject path traversal attempts. This allows an unauthenticated remote user, when a crafted POST request is made against unauthenticated API routes, to access otherwise protected API routes leading to escalation of privileges and information disclosure.
https://www.percona.com/blog/pmm-authentication-bypass-vulnerability-fixed-in-2-37-1/