CVE-2026-55157 json
Token Optimizer MCP: OS command injection in smart_user via username in get-user-info
published 2026-08-14 2 mo ago modified 2026-10-01 38 d ago also GHSA-49mq-fc6q-3h46 , EUVD-2026-88397
- cvss
- 8.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 59%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm @ooples/token-optimizer-mcp 5.1.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 38 d ago
Exploit prediction
0.88% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-49mq-fc6q-3h46 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @ooples/token-optimizer-mcp | <5.1.0 |
5.1.0 |
Affected products
- ooples token-optimizer-mcp
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
Sources
- CVE List CVE-2026-55157
- GitHub Advisory GHSA-49mq-fc6q-3h46
- NVD CVE-2026-55157
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