CKAN MCP Server: Information disclosure via verbose error reflection
cve-program · CVE-2026-73844
PublishedCKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
Read the publisher's advisoryeuvd · EUVD-2026-58724
PublishedCKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
Read the publisher's advisorynvd · CVE-2026-73844
PublishedCKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
Read the publisher's advisoryosv · GHSA-6f9w-9hf2-5rg3
Published## Summary 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: ```js } 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: ```js 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, ... }); ``` ## 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=false` error 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. ## 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 internal `ECONNREFUSED 169.254.169.254` message being reflected to the caller. ## Remediation - 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.message` from the response `data` (or replace with a correlation id) in production.
Read the publisher's advisoryAffected versions, risk and source history
Exploitation and risk
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cve-program · CVE-2026-73844
PublishedCKAN MCP Server: Information disclosure via verbose error reflection
CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
- Source published
- 14 Aug 2026 16:41:42 UTC
- Source modified
- 18 Aug 2026 02:11:05 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
euvd · EUVD-2026-58724
PublishedCKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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…
CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Aug 14, 2026, 4:41:42 PM
dateUpdated: Aug 18, 2026, 2:11:05 AM
- Source published
- Aug 14, 2026, 4:41:42 PM (timezone not stated)
- Source modified
- Aug 18, 2026, 2:11:05 AM (timezone not stated)
- Saved here
- 11 Nov 2026 16:06:15 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
EUVD CVSS 3.1 · 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
nvd · CVE-2026-73844
PublishedCKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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…
CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, 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). This vulnerability is fixed in 0.4.112.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Deferred
Weakness classifications: CWE-209 · CWE-210
Original publisher date fields
published: 2026-08-14T17:20:36.683
lastModified: 2026-09-18T20:09:01.757
- Source published
- 14 Aug 2026 17:20:36 UTC
- Source modified
- 18 Sep 2026 20:09:01 UTC
- Saved here
- 25 Oct 2026 15:19:09 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
osv · GHSA-6f9w-9hf2-5rg3
PublishedCKAN MCP Server: Information disclosure via verbose error reflection
## Summary 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: ```js } 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: ```js 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, ... }); ``` ## 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=false` error 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. ## 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 internal `ECONNREFUSED 169.254.169.254` message being reflected to the caller. ## Remediation - 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.message` from the response `data` (or replace with a correlation id) in production.
- Source published
- 3 Sep 2026 14:49:10 UTC
- Source modified
- 3 Sep 2026 15:00:09 UTC
- Saved here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Publisher rating · LOW