CVE-2026-51997

Deferred Deferred - Pending Action

Remote Code Execution in geelen mcp-remote

Publication date: 2026-09-24

Last updated on: 2026-09-25

Assigner: MITRE

Description

An issue in geelen mcp-remote 0.1.16 through 0.1.38 allows a remote attacker to execute arbitrary code via the open() functions

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-24

Last Modified

2026-09-25

Generated

2026-10-15

AI Q&A

2026-09-24

EPSS Evaluated

2026-10-13

NVD

CVE-2026-51997

EUVD

EUVD-2026-86020

Affected Vendors & Products

Vendor	Product	Version / Range
geelen	mcp-remote	From 0.1.16 (inc) to 0.1.38 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
CWE-20	The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

Attack-Flow Graph

Executive Summary

CVE-2026-51997 is a vulnerability in geelen mcp-remote versions 0.1.16 through 0.1.38 where incomplete URL validation allows a remote attacker to execute arbitrary code via the open() functions. The issue involves improper handling of URLs, enabling attackers to open restricted or internal URLs in a user's browser.

Detection Guidance

Check if your system uses mcp-remote versions 0.1.16 through 0.1.38. Inspect browser launch behavior for improper URL handling. Look for unexpected browser navigation to internal or restricted URLs.

Impact Analysis

This vulnerability could allow an attacker to interact with internal services, perform reconnaissance, or facilitate browser-mediated CSRF attacks if the target service lacks protections. Attackers might exploit it to access sensitive internal resources or execute unauthorized actions on behalf of the user.

Compliance Impact

This vulnerability could potentially violate compliance with standards like GDPR and HIPAA by enabling unauthorized access to internal services or restricted URLs through the browser. If exploited, it may allow attackers to interact with internal systems, perform reconnaissance, or facilitate browser-mediated CSRF attacks, which could lead to data breaches or unauthorized data exposure.

Mitigation Strategies

Upgrade mcp-remote to a version that includes proper URL validation. Explicitly reject loopback, private, link-local, multicast, reserved, and metadata-service addresses. Display the final origin to users before navigation.

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