CVE intelligence

CVE-2026-40034

Vulnerability intelligence

Published May 26, 2026Sources checked Nov 11, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-40034 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Jun 13, 2026

CBL-Mariner Releases

Vendor-listed releases

1.75.0-30
1.90.0-9

CISA KEVNot listedBased on the latest collected catalog

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-40034?

gix-submodule before 0.29.0 (gitoxide before 0.5.21, gix before 0.84.0) incorrectly validates the update field in .gitmodules, allowing attackers to bypass the CommandForbiddenInModulesConfiguration guard when a submodule has been initialized with only partial configuration in .git/config.

An attacker can inject arbitrary shell commands via the update field in .gitmodules that will be executed when Submodule::update() is called on a previously-initialized submodule, enabling remote code execution.

Source: NVD