CVE-2026-55156
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.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Puntuación base: 5.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.45%
- Percentil entre todas las CVEs puntuadas: 37
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access90 % - Impacto principal
T1005Data from Local Systemcollection85 %
API HTTP sin autenticación (AV:N, PR:N) permite lectura no autorizada de archivos mediante path traversal en parámetro sessionId (CWE-22).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-22
Referencias
- https://github.com/ooples/token-optimizer-mcp/commit/b4ee96dac799cbfba0a9f9c17844ce9d613cbcc7
- https://github.com/ooples/token-optimizer-mcp/releases/tag/v5.1.0
- https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5
- https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-55156",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-55156",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-28T18:10:48.242882Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.3,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "ooples",
"product": "token-optimizer-mcp",
"versions": [
{
"status": "affected",
"version": "< 5.1.0"
}
]
}
]
}
],
"published": "2026-09-28T18:17:23.203",
"references": [
{
"url": "https://github.com/ooples/token-optimizer-mcp/commit/b4ee96dac799cbfba0a9f9c17844ce9d613cbcc7",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ooples/token-optimizer-mcp/releases/tag/v5.1.0",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ooples/token-optimizer-mcp/security/advisories/GHSA-76pc-mqxp-3rq5",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-22"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"lastModified": "2026-09-30T19:57:08.043",
"sourceIdentifier": "security-advisories@github.com"
}