CVE-2026-53509
CKAN MCP Server
- Severity
- Medium
- Published
- August 21, 2026
- Last modified
- October 12, 2026
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`.
CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
Weakness
- CWE-918 Server-side request forgery
References
Listed in
More CKAN MCP Server CVEs
The SSRF guard `validateServerUrl` (added for CVE-2026-33060, extended for CVE-2026-53509) validates only the hostname string and never resolves DNS.
CanonicalizeParams in src/utils/cache.ts serializes request parameters with unescaped ampersand, equals-sign, and vertical-bar delimiters, allowing different logical parameter sets used by buildCacheKey to…
The ckan_get_mqa_quality and ckan_get_mqa_quality_details tools in src/tools/quality.ts use isValidMqaServer to validate the server_url parameter with a prefix-only regular expression for dati.gov.it,…
Error paths reflect raw upstream response bodies and internal exception messages back to the caller instead of a sanitized, generic message.
Versions prior to 0.4.85 provide tools including ckan_package_search and sparql_query that accept a base_url parameter, making HTTP requests to arbitrary endpoints without restriction.