CVE-2026-61568

Deferred Deferred - Pending Action

Remote Code Execution in zereight mcp-gitlab

Publication date: 2026-09-15

Last updated on: 2026-09-30

Assigner: GitHub, Inc.

Description

`@zereight/mcp-gitlab` is a Model Context Protocol server for GitLab. Versions prior to 2.1.30 expose the 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. Version 2.1.30 contains a patch.

CVSS Scores

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Meta Information

Published

2026-09-15

Last Modified

2026-09-30

Generated

2026-10-06

AI Q&A

2026-09-16

EPSS Evaluated

2026-10-04

NVD

CVE-2026-61568

Affected Vendors & Products

Vendor	Product	Version / Range
zereight	mcp-gitlab	to 2.1.30 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-350	The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname.

Attack-Flow Graph

Executive Summary

The vulnerability in @zereight/mcp-gitlab versions prior to 2.1.30 allows a malicious web page to bypass security controls using DNS rebinding. This technique tricks a victim's browser into routing requests to a local MCP listener while maintaining attacker-controlled Host and Origin headers. The server fails to validate these headers properly, leading to unauthorized access to the MCP initialization path.

Detection Guidance

Check if your @zereight/mcp-gitlab version is prior to 2.1.30. Inspect network traffic for unexpected Streamable HTTP MCP endpoint requests. Look for DNS rebinding attempts targeting local MCP listeners.

Impact Analysis

This vulnerability could allow an attacker to execute arbitrary code or access sensitive data on your system. If you run the vulnerable version, a malicious website could trick your browser into sending requests to your local MCP server, potentially compromising your system or data.

Mitigation Strategies

Upgrade @zereight/mcp-gitlab to version 2.1.30 or later. Configure Host and Origin allowlists for the Streamable HTTP MCP endpoint. Block suspicious DNS rebinding attempts at the network level.

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