Summary
CKAN MCP Server: Information disclosure via verbose error reflection
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).
Affected code
src/utils/http.ts, the entire decoded upstream body is embedded in the thrown error, which formatCkanError returns to the tool result:
} else {
throw new CkanApiError(
`CKAN API returned success=false: ${JSON.stringify(decodedData)}`, // full body reflected
undefined,
action
);
}
src/worker.ts, the catch-all handler returns the raw Error.message in the JSON-RPC data field:
return new Response(JSON.stringify({
jsonrpc: '2.0',
error: { code: -32603, message: 'Internal error',
data: error instanceof Error ? error.message : String(error) }, // raw internal message
id: null
}), { status: 500, ... });
Proof of concept
poc/error-disclosure-poc.mjs reproduces both paths and shows an upstream body
(containing a simulated DB error with an internal IP) and an internalECONNREFUSED 169.254.169.254 message being reflected to the caller.
Impact
- Reflects arbitrary upstream response content to the caller. Combined with the SSRF vectors (advisories #01/#06), an attacker can use this as the read channel: point the server at an internal endpoint and receive its body inside the
success=falseerror string (turning otherwise-blind SSRF into a semi-blind/return-value SSRF for any host that reaches the guards). - Leaks internal operational detail via exception messages: node error codes and target addresses (e.g.
ECONNREFUSED 169.254.169.254:80), which confirm internal reachability and infrastructure, and any stack/path fragments an upstream includes. - Aids reconnaissance and error-oracle attacks against the deployment.
Severity is Low on its own (the server holds no credentials of its own and sends no auth upstream), but it meaningfully amplifies the SSRF findings by providing a response-content channel.
CVE-2026-73844 has a CVSS score of 3.7 (Low). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.4.112); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
- Return generic, action-scoped error messages to the caller; log the detailed
upstream body/exception server-side only. - Do not embed
JSON.stringify(decodedData)in caller-visible errors; cap and
redact any reflected content. - In the Workers catch-all, omit
error.messagefrom the responsedata(or
replace with a correlation id) in production.
Frequently Asked Questions
- What is CVE-2026-73844? CVE-2026-73844 is a low-severity security vulnerability in @aborruso/ckan-mcp-server (npm), affecting versions < 0.4.112. It is fixed in 0.4.112.
- How severe is CVE-2026-73844? CVE-2026-73844 has a CVSS score of 3.7 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of @aborruso/ckan-mcp-server are affected by CVE-2026-73844? @aborruso/ckan-mcp-server (npm) versions < 0.4.112 is affected.
- Is there a fix for CVE-2026-73844? Yes. CVE-2026-73844 is fixed in 0.4.112. Upgrade to this version or later.
- Is CVE-2026-73844 exploitable, and should I be worried? Whether CVE-2026-73844 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-73844 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-73844? Upgrade
@aborruso/ckan-mcp-serverto 0.4.112 or later.