lowAgent ThreatData Exfiltration

CKAN MCP Server Verbose Error Information Disclosure

First seen Aug 14, 2026 · Updated Aug 14, 2026 · CVSS 3.7

information-disclosuremcperror-handlingssrf-adjacentverbose-errorsASI09 · Human Trust ExploitationSurface: Tool LayerPropagation: None

The CKAN MCP Server, prior to version 0.4.112, leaks raw upstream response bodies and internal exception details (hostnames, internal IPs, DB errors, stack fragments) to callers when errors occur or when the server is redirected to a non-CKAN host. This is a low-severity information disclosure issue rather than a direct compromise vector, but it can aid reconnaissance for further attacks, especially if combined with SSRF-style redirection. The vendor has already released a fix.

Technical Analysis

The MCP server's error-handling paths fail to sanitize responses before returning them to the calling agent or client, instead passing through verbatim upstream content and internal exception text. The entry point is any tool call that triggers an error condition, either through malformed requests, a misconfigured/redirected target host, or genuine internal exceptions. An attacker who can influence the target host (via SSRF or configuration tampering) or trigger backend errors gains visibility into internal network topology, hostnames, and database error details that should remain server-side. This crosses the tool-to-caller boundary within MCP, allowing an LLM agent (and potentially an end user surfaced through that agent) to receive and act on sensitive internal diagnostic data, which could inform follow-on attacks such as targeted SSRF or credential harvesting.

Affected Systems

CKAN MCP Server; protocols: MCP

Detection Signatures

  • Log entries showing MCP tool error responses containing internal IP addresses, hostnames, or stack traces
  • Unexpected non-CKAN response bodies returned from CKAN MCP Server tool calls
  • Database error strings or exception class names appearing in agent-facing output
  • Repeated tool calls targeting unusual or redirected hostnames prior to error responses

Remediation Steps

  1. 1

    Upgrade CKAN MCP Server

    Update to version 0.4.112 or later, which sanitizes error responses before returning them to callers.

  2. 2

    Sanitize error handling

    Ensure all error paths return generic, non-identifying messages and log detailed internal errors server-side only.

  3. 3

    Restrict outbound targets

    Apply allowlisting or network egress controls to prevent the MCP server from being pointed at or redirected to arbitrary/internal hosts (mitigating SSRF exposure).

  4. 4

    Review agent-facing logs

    Audit historical logs for leaked internal hostnames, IPs, or stack traces that may have been exposed to callers or downstream agents.

CVE / Advisory IDs

CVE-2026-73844

Industries Most Exposed

governmentopen-data/public-sectorresearchnon-profittechnology

Sources

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