{"id":"CVE-2026-53509","revision":"b3f4390b88e24f77b6f6eadc36017ef1","records":[{"revision":"b3f4390b88e24f77b6f6eadc36017ef1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53509","aliases":[],"title":"@aborruso/ckan-mcp-server: SSRF via base_url allows access to internal networks (Potential fix bypass of CVE-2026-33060)","description":"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`.","state":0,"publishedAt":"2026-08-21T21:21:20.897+00:00","modifiedAt":"2026-08-21T21:42:22.5+00:00","affected":[{"ecosystem":"Vendor product","name":"ckan-mcp-server","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"ondata\",\n                    \"product\": \"ckan-mcp-server\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 0.4.106\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","score":5.7,"severity":"MEDIUM"}],"references":["https://github.com/ondata/ckan-mcp-server/security/advisories/GHSA-g84h-j7jj-x32p","https://github.com/advisories/GHSA-3xm7-qw7j-qc8v","https://github.com/ondata/ckan-mcp-server/releases/tag/v0.4.106"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53509","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53509","identifiers":["CVE-2026-53509"]},"retained":false,"historicalAffected":[]}],"coverage":[]}