FKIE_CVE-2026-53509
Vulnerability from fkie_nvd - Published: 2026-08-21 22:16 - Updated: 2026-10-12 16:10
Severity
Summary
CKAN MCP Server is a tool for querying CKAN open data portals. A known vulnerability CVE-2026-33060 indicated tools including ckan_package_search and sparql_query that accept a base_url parameter had the risk of making HTTP requests to arbitrary endpoints without restriction. A fix was applied to filter out ip addresses. However, a method to bypass exists prior to version 0.4.106. CKAN MCP Server validates caller-supplied CKAN server URLs by inspecting only the parsed hostname string before issuing outbound HTTP requests. In `src/utils/http.ts`, hostname aliases such as `ip6-localhost` are not equal to `localhost`, are not dotted IPv4 literals, and are not bracketed IPv6 literals, so they pass the SSRF filter but can resolve to loopback when the server performs the request. A remote MCP caller that can invoke CKAN tools with a `server_url` can therefore make the server connect to local or private addresses and, for CKAN-shaped responses, receive response-derived data. The updated fix in version 0.4.106 replaced the single `hostname === 'localhost'` check with a blocked-hostname `Set` covering `ip6-localhost` and `ip6-loopback`.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"product": "ckan-mcp-server",
"vendor": "ondata",
"versions": [
{
"status": "affected",
"version": "\u003c 0.4.106"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "CKAN MCP Server is a tool for querying CKAN open data portals. A known vulnerability CVE-2026-33060 indicated tools including ckan_package_search and sparql_query that accept a base_url parameter had the risk of making HTTP requests to arbitrary endpoints without restriction. A fix was applied to filter out ip addresses. However, a method to bypass exists prior to version 0.4.106. CKAN MCP Server validates caller-supplied CKAN server URLs by inspecting only the parsed hostname string before issuing outbound HTTP requests. In `src/utils/http.ts`, hostname aliases such as `ip6-localhost` are not equal to `localhost`, are not dotted IPv4 literals, and are not bracketed IPv6 literals, so they pass the SSRF filter but can resolve to loopback when the server performs the request. A remote MCP caller that can invoke CKAN tools with a `server_url` can therefore make the server connect to local or private addresses and, for CKAN-shaped responses, receive response-derived data. The updated fix in version 0.4.106 replaced the single `hostname === \u0027localhost\u0027` check with a blocked-hostname `Set` covering `ip6-localhost` and `ip6-loopback`."
},
{
"lang": "es",
"value": "El Servidor CKAN MCP es una herramienta para consultar portales de datos abiertos CKAN. Una vulnerabilidad conocida CVE-2026-33060 indicaba que herramientas, incluyendo ckan_package_search y sparql_query, que aceptan un par\u00e1metro base_url, ten\u00edan el riesgo de realizar solicitudes HTTP a puntos finales arbitrarios sin restricci\u00f3n. Se aplic\u00f3 una correcci\u00f3n para filtrar direcciones IP. Sin embargo, existe un m\u00e9todo para eludirlo anterior a la versi\u00f3n 0.4.106. El Servidor CKAN MCP valida las URL de los servidores CKAN proporcionadas por el llamador inspeccionando solo la cadena de nombre de host analizada antes de emitir solicitudes HTTP salientes. En \u0027src/utils/http.ts\u0027, alias de nombre de host como \u0027ip6-localhost\u0027 no son iguales a \u0027localhost\u0027, no son literales IPv4 con puntos y no son literales IPv6 entre corchetes, por lo que pasan el filtro SSRF pero pueden resolverse a loopback cuando el servidor realiza la solicitud. Un llamador MCP remoto que puede invocar herramientas CKAN con una \u0027server_url\u0027 puede, por lo tanto, hacer que el servidor se conecte a direcciones locales o privadas y, para respuestas con formato CKAN, recibir datos derivados de la respuesta. La correcci\u00f3n actualizada en la versi\u00f3n 0.4.106 reemplaz\u00f3 la \u00fanica verificaci\u00f3n \u0027hostname === \u0027localhost\u0027\u0027 con un \u0027Set\u0027 de nombres de host bloqueados que cubre \u0027ip6-localhost\u0027 y \u0027ip6-loopback\u0027."
}
],
"id": "CVE-2026-53509",
"lastModified": "2026-10-12T16:10:00.220",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.7,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.1,
"impactScore": 3.6,
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-53509",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-21T21:35:04.552283Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-21T22:16:38.993",
"references": [
{
"source": "security-advisories@github.com",
"url": "https://github.com/advisories/GHSA-3xm7-qw7j-qc8v"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/ondata/ckan-mcp-server/releases/tag/v0.4.106"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/ondata/ckan-mcp-server/security/advisories/GHSA-g84h-j7jj-x32p"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-918"
}
],
"source": "security-advisories@github.com",
"type": "Primary"
}
]
}
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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