ondata ckan-mcp-server up to 0.4.105 Hostname Validation src/utils/http.ts base_url server-side request forgery

Summaryinfo

A vulnerability was found in ondata ckan-mcp-server up to 0.4.105. It has been rated as problematic. The impacted element is an unknown function of the file src/utils/http.ts of the component Hostname Validation. The manipulation of the argument base_url leads to server-side request forgery. This vulnerability is uniquely identified as CVE-2026-53509. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in ondata ckan-mcp-server up to 0.4.105. This issue affects an unknown function of the file src/utils/http.ts of the component Hostname Validation. The manipulation of the argument base_url with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Impacted is confidentiality. The summary by CVE is:

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`.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-53509 since 06/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 0.4.106 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• ondata

Name

• ckan-mcp-server

Version

• 0.4.105

Website

• Product: https://github.com/ondata/ckan-mcp-server/

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