CKAN MCP Server suffers from an allowlist bypass that is caused by the use of an unanchored regular expression in the isValidMqaServer routine. The flaw permits maliciously crafted server_url values that include suffix-host and URL-userinfo components to be treated as valid, meaning the tool can be coaxed into treating an attacker‑controlled host as a trusted MQA server. The result is that the tool will fetch data from the malicious host and return a spoofed response, potentially exposing sensitive information or misleading users about the authenticity of the data. This vulnerability falls under CWE‑20 (Improper Input Validation), CWE‑625 (Improper Handling of Cryptographic Parameters), and CWE‑918 (Server‑Side Request Forgery).

All releases of CKAN MCP Server prior to version 0.4.112 are vulnerable. The issue is fixed in the release candidate tagged v0.4.112. The product is provided by the vendor "ondata" as CKAN MCP Server.

The CVSS score is 5.3, indicating moderate severity. EPSS information is not available, making it difficult to gauge current exploitation likelihood, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is an attacker supplying a crafted server_url parameter to the tool; this could be performed by a user of the tool or via a compromised system running the tool, thereby enabling an attacker to manipulate the data retrieved by the tool. Given the absence of active exploitation data, the immediate risk is moderate but should be mitigated promptly by applying available fixes.