CVE-2026-55156 Details
Description
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.
A path traversal vulnerability has been identified in the Token Optimizer MCP dashboard HTTP server, specifically in version 5.0.1. The issue arises in the '/api/session-summary' and '/api/session-events' endpoints, which lack authentication middleware, allowing any network-accessible client to access them without credentials. The vulnerability allows an unauthenticated attacker to read any '.jsonl' file from the server's filesystem by exploiting the unsanitized 'sessionId' query parameter, which is directly concatenated into a file path. Node.js normalizes '..' segments at resolution time, enabling the traversal. This flaw has been patched in version 5.1.0.
Users can upgrade to Token Optimizer MCP version 5.1.0 or later, where this vulnerability has been patched. In addition, it is recommended to add authentication middleware to the '/api/*' routes and validate the 'sessionId' format before use, rejecting any values that do not match a strict allowlist.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 28, 2026CISA-ADP
Assessed Sep 28, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5 | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/ooples/token-optimizer-mcp/commit/b4ee96dac799cbfba0a9f9c17844ce9d613cbcc7 | [email protected] | Source CodeVendor |
| https://github.com/ooples/token-optimizer-mcp/releases/tag/v5.1.0 | [email protected] | Release NotesVendor |
| https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-22 | Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| ooples Token Optimizer MCP | 5.0.1 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 28, 2026 | CVE Modified | CISA-ADP |
| Sep 28, 2026 | New CVE Received | [email protected] |