CVE-2026-53509

mediumpriority · track · 0EPSS 0.004 · 32 %ileUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.38% (32nd) EPSS
CVSS 5.7 · medium
Is it mine?
1 products
Check your exposure
Who says so?
1 sources
osv

EPSS · scored 2026-10-27

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`.

01

cvss

Technical severity, 0–10. One row per scoring source.

5.7
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.7mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:Nsecondary · security-advisories@github.comexploitability 2.1 · impact 3.6
v3.15.7mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:Nsecondary · OSV
v3.15.2mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-918USprimaryCWE-918US
04

affected products (1)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • GHSA-g84h-j7jj-x32p@aborruso/ckan-mcp-server: SSRF via base_url allows access to internal networks (Potential fix bypass of CVE-2026-33060)2026-07-07ghsa · osvUS

    ### Summary 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. ### Details 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. ### Fix Replaced the single `hostname === 'localhost'` check with a blocked-hostname `Set` covering `ip6-localhost` and `ip6-loopback`. Patched in commit `c761045a1b7c5f40d2626540dd2ef1d4feb91f8c`. --- @aborruso/ckan-mcp-server thanks **hibrian827** for responsibly disclosing this issue.

06

sources

Which sources assert this record, and when.

osvNVDCVE.orgMITRE
published 2026-08-21modified 2026-08-21
08

references (3) nvd

External citations — patches, advisories, analysis.

scry

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