@zereight/mcp-gitlab: DNS rebinding reaches local Streamable HTTP MCP transport

Exploitation

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

CVSS

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

EPSS

• CVE-2026-61568: 0.53% estimated exploitation activity in the next 30 days; percentile 45.03 (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.

@zereight/mcp-gitlab exposes its Streamable HTTP MCP endpoint without an effective Host or Origin allowlist. A malicious web page can use DNS rebinding to route browser requests to a victim's local MCP listener while preserving an attacker-controlled Host and Origin. The server accepts those headers and reaches the MCP initialization path instead of rejecting the request at the HTTP boundary. This is CWE-350, Reliance on Reverse DNS Resolution for a Security-Critical Action. The affected package is @zereight/mcp-gitlab version 2.1.18 at commit 74a8c834424ff557ad8bc6f225e4dc5acf80aa13. The vulnerable transport setup is in index.ts. Express JSON parsing is installed globally before any MCP route-level Host or Origin allowlist: The Streamable HTTP transport is then created without the SDK DNS-rebinding controls: The transport constructor does not set enableDnsRebindingProtection, allowedHosts, or allowedOrigins. The server also does not add an Express middleware that rejects unexpected…

Published by the source

15 Sep 2026, 20:54 UTC

Last modified by the source

15 Sep 2026, 21:00 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vmp7-252j-cwp7

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-vmp7-252j-cwp7

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-vmp7-252j-cwp7

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# Patch Next advisory brief: CVE-2026-61568

Advisory: @zereight/mcp-gitlab: DNS rebinding reaches local Streamable HTTP MCP transport
IDs: CVE-2026-61568, GHSA-vmp7-252j-cwp7
Record: https://patchnext.com/advisories/cve-2026-61568 (revision 3, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @zereight/mcp-gitlab 2.1.30. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @zereight/mcp-gitlab: affected < 2.1.30; fixed in 2.1.30

## Suggested inspection (read-only)
- `npm ls @zereight/mcp-gitlab --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 @zereight/mcp-gitlab.
- 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-vmp7-252j-cwp7 (GitHub-reviewed advisory GHSA-vmp7-252j-cwp7 lists affected ranges: npm @zereight/mcp-gitlab >=0 <2.1.30)
- Verified: https://osv.dev/vulnerability/GHSA-vmp7-252j-cwp7 (OSV record GHSA-vmp7-252j-cwp7 lists affected ranges: npm @zereight/mcp-gitlab >=0 <2.1.30 (fixed))

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