Vulnerability · Published Sep 28, 2026 · Assigned by GitHub_M
CVE-2026-55157Token Optimizer MCP: OS command injection in smart_user via username in get-user-info
High 8.4
In plain English
A high-severity OS command injection in token-optimizer-mcp from ooples. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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, token-optimizer-mcp is vulnerable to OS command injection in the smart_user tool. Any MCP client that can call the smart_user tool can execute arbitrary shell commands through the username argument of the get-user-info operation. The commands execute with the privileges of the user running the token-optimizer-mcp server. This issue has been patched in version 5.1.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @ooples/token-optimizer-mcp | 5.1.0 | GHSA-49mq-fc6q-3h46 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ooples | token-optimizer-mcp | < 5.1.0 |
Weakness: CWE-78 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H