CVE-2026-117560

ATXP Gemini CLI extension interpolates MCP arguments into a shell

ATXP · ATXP Gemini CLI extension

First documented disclosure · Review checkpoint

Summary

A malicious MCP argument could execute commands under the extension user's account.

Severity and exploitation evidence

High · 8.5/10 · CVSS 4.0. Severity source.

Exploitation not established: The reviewed sources describe a vulnerability and demonstration, not established malicious exploitation.

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

The runAtxp helper builds an executable shell string from inadequately escaped tool parameters.

Conditions required

Ability to influence an extension tool invocation, directly or by persuading an agent through untrusted content.

Potential impact

Host command execution and potential access to locally available credentials.

Affected versions and configurations

Through 1.0.0.

Fix and mitigation status

No fixed version established in the reviewed sources.

Practical next steps

Disable affected tools until patched; replace shell-string execution with explicit argument arrays.

Operating lesson

Text from email, messages and search results must not become executable syntax.

Evidence and limits

The unchanged October 23 issue predates October 27 assignment. This affects the extension, not an established breach of Gemini or Google services.

Sources