CVE-2026-55157

HIGHPre-NVD 8.48.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7% (51st percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
8.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 8.4Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
8.4
EG Score
8.4HIGHmedium confidence
EG Risk
54
EG Risk 54/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity84% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
51st
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 14, 2026

Last Modified

October 1, 2026

Advisory Details (3)

Auto-updated Sep 28, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

v5.1.0

Patch available: ooples/token-optimizer-mcp v5.1.0

https://github.com/ooples/token-optimizer-mcp/releases/tag/v5.1.0
github_commit Patch Available

commit b4ee96dac799 (ooples/token-optimizer-mcp)

Patch available: ooples/token-optimizer-mcp v5.1.0 (contains commit b4ee96dac799)

https://github.com/ooples/token-optimizer-mcp/commit/b4ee96dac799cbfba0a9f9c17844ce9d613cbcc7
github Patch Available🟡 PoC Available

OS command injection in smart_user via username in get-user-info · Advisory · ooples/token-optimizer-mcp · GitHub

https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-49mq-fc6q-3h46

Vendor Advisories for CVE-2026-55157(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
@ooples/token-optimizer-mcp—
  • every version up to 5.1.0: fixed in 5.1.0
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 15× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 12:57 UTCEG score recompute
  2. 2026-10-04 23:22 UTCEPSS rescore
  3. 2026-10-03 19:40 UTCEG score recompute
  4. 2026-10-03 14:26 UTCEPSS rescore
  5. 2026-10-02 18:30 UTCEG score recompute
  6. 2026-10-02 17:56 UTCEPSS rescore
  7. 2026-10-02 07:18 UTCEG score recompute
  8. 2026-10-01 19:50 UTCEPSS rescore
  9. 2026-10-01 15:25 UTCEG score recompute
  10. 2026-10-01 14:51 UTCEG score recompute
  11. 2026-09-30 20:04 UTCEG score recompute
  12. 2026-09-30 15:03 UTCEPSS rescore
  13. 2026-09-29 15:22 UTCEPSS rescore
  14. 2026-09-29 05:34 UTCEG score recompute
  15. 2026-09-28 18:22 UTCEG score recompute
  16. 2026-08-14 22:25 UTCEG score recompute

Related CVEs(same product + same CWE)

Same product

1 shown

npm:@ooples/token-optimizer-mcp

Frequently asked(5)

What is CVE-2026-55157?
CVE-2026-55157 is a high vulnerability published on August 14, 2026. 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 smartuser tool. Any MCP client that can call the smartuser tool…
When was CVE-2026-55157 disclosed?
CVE-2026-55157 was first published on August 14, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55157 actively exploited?
CVE-2026-55157 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55157?
CVE-2026-55157 has a CVSS base score of 8.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55157?
A fix for CVE-2026-55157 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55157 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55157

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