Cyber Posture

CVE-2026-40034

HighPublic PoC
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 26 May 2026

Published
26 May 2026
Modified
28 May 2026
KEV Added
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Patch
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CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0002 4.6th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-40034 is a high-severity Command Injection (CWE-77) vulnerability in Anthropic (inferred from references). Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Unix Shell (T1059.004); ranked at the 4.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Unix Shell (T1059.004).
Threat & Defense Details

MITRE ATT&CK Enterprise TechniquesAI

T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

CWE-77 command injection in .gitmodules update field directly enables arbitrary Unix shell command execution on Submodule::update().

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

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…

more

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.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-77
OWASP Top 10 Web 2025
A05:2025

Affected Products

Anthropic
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inferred from references and description; NVD did not file a CPE for this CVE

EU & UK References

References