CVE-2026-55156 — Token Optimizer MCP: Unauthenticated Path Traversal in Dashboard Session Log API Endpoints
Token Optimizer MCP measures token savings per AI coding agent, optimizes context, and shares a live local knowledge graph across 16 CLI clients. Prior to version 5.1.0, the das…
Published: 2026-09-28 · CVSS: 5.3 · CVSS 3.1
Token Optimizer MCP measures token savings per AI coding agent, optimizes context, and shares a live local knowledge graph across 16 CLI clients. Prior to version 5.1.0, the dashboard HTTP server in token-optimizer-mcp exposes /api/session-summary and /api/session-events with no authentication middleware — any network-accessible client can reach them without credentials. Both handlers concatenate the caller-supplied sessionId query parameter directly into a filesystem path via path.join, and Node.js normalizes .. segments at resolution time, allowing an unauthenticated attacker to read any .jsonl file reachable from the server's filesystem. This issue has been patched in version 5.1.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7