{"id":"CVE-2026-53509","aliases":["GHSA-g84h-j7jj-x32p"],"url":"https://o3.security/vulnerability/CVE-2026-53509","summary":"@aborruso/ckan-mcp-server: SSRF via base_url allows access to internal networks (Potential fix bypass of CVE-2026-33060)","details":"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`.","published":"2026-08-21T21:21:20.897Z","modified":"2026-09-11T03:30:43.257379326Z","cvss":{"score":5.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N"},"epss":{"score":0.00217,"percentile":0.12279,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@aborruso/ckan-mcp-server","fixedVersion":"0.4.106"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/ondata/ckan-mcp-server/releases/tag/v0.4.106"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53509.json"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-3xm7-qw7j-qc8v"},{"type":"ADVISORY","url":"https://github.com/ondata/ckan-mcp-server/security/advisories/GHSA-g84h-j7jj-x32p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53509"},{"type":"PACKAGE","url":"https://github.com/ondata/ckan-mcp-server"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-11T03:30:43.257379326Z"}}