CVE-2026-58483
mcp-searxng is a Model Context Protocol server that gives AI assistants web search and URL-reading capabilities through SearXNG. Prior to 1.7.1, web_url_read in src/index.ts passes a caller-supplied URL to readUrlContent() in src/url-reader.ts, where checkContentLength() treats a missing Content-Length header as an inconclusive preflight and the normal and error paths then consume the complete body with response.text(). A server that omits Content-Length can therefore bypass URL_READ_MAX_CONTENT_LENGTH_BYTES and force unbounded memory use. The resulting string is also processed by NodeHtmlMarkdown.translate(), increasing CPU consumption and allowing an unauthenticated HTTP client to cause denial of service. This issue is fixed in version 1.7.1.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.67%
- Percentil entre todas las CVEs puntuadas: 50
- Fecha de la puntuación: 6/10/2026
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 access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
AV:N/PR:N/UI:N permite explotación remota sin autenticación (T1190). Omitir Content-Length causa consumo de memoria y CPU sin límite, generando DoS de aplicación (T1499.004).
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 (2)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-400
Referencias
- https://github.com/ihor-sokoliuk/mcp-searxng/commit/f5a947ed1650daed10fbdcd53c0db5a86489ffe4
- https://github.com/ihor-sokoliuk/mcp-searxng/pull/121
- https://github.com/ihor-sokoliuk/mcp-searxng/releases/tag/v1.7.1
- https://github.com/ihor-sokoliuk/mcp-searxng/security/advisories/GHSA-xcqx-9jf5-w339
- https://github.com/ihor-sokoliuk/mcp-searxng/security/advisories/GHSA-xcqx-9jf5-w339
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-58483",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-58483",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-15T18:22:16.482545Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "ihor-sokoliuk",
"product": "mcp-searxng",
"versions": [
{
"status": "affected",
"version": "< 1.7.1"
}
]
}
]
}
],
"published": "2026-09-15T18:17:25.873",
"references": [
{
"url": "https://github.com/ihor-sokoliuk/mcp-searxng/commit/f5a947ed1650daed10fbdcd53c0db5a86489ffe4",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ihor-sokoliuk/mcp-searxng/pull/121",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ihor-sokoliuk/mcp-searxng/releases/tag/v1.7.1",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ihor-sokoliuk/mcp-searxng/security/advisories/GHSA-xcqx-9jf5-w339",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/ihor-sokoliuk/mcp-searxng/security/advisories/GHSA-xcqx-9jf5-w339",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-400"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "mcp-searxng is a Model Context Protocol server that gives AI assistants web search and URL-reading capabilities through SearXNG. Prior to 1.7.1, web_url_read in src/index.ts passes a caller-supplied URL to readUrlContent() in src/url-reader.ts, where checkContentLength() treats a missing Content-Length header as an inconclusive preflight and the normal and error paths then consume the complete body with response.text(). A server that omits Content-Length can therefore bypass URL_READ_MAX_CONTENT_LENGTH_BYTES and force unbounded memory use. The resulting string is also processed by NodeHtmlMarkdown.translate(), increasing CPU consumption and allowing an unauthenticated HTTP client to cause denial of service. This issue is fixed in version 1.7.1."
}
],
"lastModified": "2026-09-30T17:51:56.193",
"sourceIdentifier": "security-advisories@github.com"
}