CVE-2026-52830 fast-mcp-telegram: Bearer token path traversal bypasses reserved Telegram session protection

fast-mcp-telegram is a Telegram MCP Server. Prior to 0.19.1, fast-mcp-telegram validates HTTP Bearer tokens by joining the raw token string into a session-file path. The verifier rejects the exact reserved token telegram, but it does not reject path separators or normalize the path before checkin...