SearXNG Basic Authentication Credentials Exposed Through MCP Logs and JSON-RPC Error Responses

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.5 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary mcp-searxng version 1.11.0 exposes SearXNG Basic Authentication credentials embedded in the SEARXNGURL environment variable. When the server starts in STDIO mode and an MCP client connects, the complete SEARXNGURL, including its username and password, is sent to the client through an MCP notifications/message logging notification. Additionally, when URL validation fails, the complete credential-bearing URL is included in the configuration error. This error is logged through MCP and returned to the client as a JSON-RPC error response. For example, a value such as: is exposed without redaction. A connected MCP client or anyone with access to captured server logs may recover the SearXNG credentials and use them to access the configured SearXNG instance. The issue was confirmed in: Suggested severity: Medium Details mcp-searxng supports SearXNG Basic Authentication by embedding credentials in the URL userinfo component: The project contains a redaction function named…

Published by the source

19 Aug 2026, 19:32 UTC

Last modified by the source

19 Aug 2026, 19:32 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hjwh-xvfw-qrwj

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# Patch Next advisory brief: GHSA-hjwh-xvfw-qrwj

Advisory: SearXNG Basic Authentication Credentials Exposed Through MCP Logs and JSON-RPC Error Responses
IDs: GHSA-hjwh-xvfw-qrwj
Record: https://patchnext.com/advisories/ghsa-hjwh-xvfw-qrwj (revision 1, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mcp-searxng 1.12.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm mcp-searxng: affected < 1.12.0; fixed in 1.12.0

## Suggested inspection (read-only)
- `npm ls mcp-searxng --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mcp-searxng.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hjwh-xvfw-qrwj (GitHub-reviewed advisory GHSA-hjwh-xvfw-qrwj lists affected ranges: npm mcp-searxng >=0 <1.12.0)

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