The MCP Apps UI resource (an interactive DataStore table rendered in the host's webview/iframe) communicates with its parent via postMessage. Its inbound message listener performs no event.origin validation, and its outbound messages are sent with target origin '*'. Any window/frame able to reach the document can inject data into the table and interfere with the MCP UI handshake, and the UI's own JSON-RPC messages are broadcast without an origin restriction.
The SSRF guard validateServerUrl (added for CVE-2026-33060, extended for CVE-2026-53509) validates only the hostname string and never resolves DNS. Any caller-supplied server_url whose hostname resolves to an internal address passes the guard, so the server issues requests to loopback and cloud metadata (169.254.169.254). This is a third bypass of the same guard, still present in the current latest 0.4.107, and it reaches IMDS — strictly more than CVE-2026-53509, which only …
Error paths reflect raw upstream response bodies and internal exception messages back to the caller instead of a sanitized, generic message. When the server is pointed at (or redirected/SSRF'd to) a host that returns a non-CKAN response, or when an internal exception occurs, the caller receives verbatim upstream content and internal detail (hostnames, internal IPs, DB errors, stack fragments).
The response cache derives its key from an ambiguous string serialization of the request parameters. canonicalizeParams joins sorted ${key}=${value} pairs with & and does not escape &, =, or the | field separators used in buildCacheKey. Two different logical parameter sets can therefore serialize to the same key and share one cache entry. Because the cached value is whatever the upstream returned for whichever request populated the entry first, an …
The ckan_get_mqa_quality and ckan_get_mqa_quality_details tools restrict their server_url argument to dati.gov.it via a regular expression. The regex is anchored only at the start and places no boundary after the host, so any URL whose host merely begins with dati.gov.it — or that uses dati.gov.it as URL userinfo before an @ — passes validation while actually targeting an attacker-controlled host.
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.
The @aborruso/ckan-mcp-server MCP server provides tools including ckan_package_search and sparql_query that accept a base_url parameter, making HTTP requests to arbitrary endpoints without restriction. A CKAN portal client has no legitimate reason to contact cloud metadata or internal network services.