SearXNG MCP Server: Additional hardened-mode SSRF bypasses

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54689: 0.19% estimated exploitation activity in the next 30 days; percentile 8.73 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary mcp-searxng has a hardened-mode URL-reading feature intended to prevent weburlread from reaching private or internal network resources. PR #79 appears to address one SSRF class: hostnames that resolve to private or internal addresses under hardened mode. I tested PR #79 locally and confirmed that it blocks the DNS-resolves-to-loopback case. However, several other hardened-mode SSRF bypasses still appear to remain: 1. Redirects from an allowed first-hop URL to a loopback/internal URL are followed without re-validating the redirect target. 2. 0.0.0.0 is not treated as an internal/special address. 3. IPv4-mapped IPv6 literals can bypass private-address checks after URL canonicalization. With hardened mode enabled and private URLs not explicitly allowed, weburlread was still able to fetch and return content from a local loopback sentinel service in all three cases. Tested configuration The MCP server was driven over stdio. The test target was a harmless internal sentinel HTTP…

Published by the source

19 Aug 2026, 19:23 UTC

Last modified by the source

19 Aug 2026, 19:23 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wppf-h75h-6pm6

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# Patch Next advisory brief: CVE-2026-54689

Advisory: SearXNG MCP Server: Additional hardened-mode SSRF bypasses
IDs: CVE-2026-54689, GHSA-wppf-h75h-6pm6
Record: https://patchnext.com/advisories/cve-2026-54689 (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 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mcp-searxng 1.2.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm mcp-searxng: affected < 1.2.1; fixed in 1.2.1

## 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-wppf-h75h-6pm6 (GitHub-reviewed advisory GHSA-wppf-h75h-6pm6 lists affected ranges: npm mcp-searxng >=0 <1.2.1)

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