CVE-2026-40034
CVE-2026-40034 is a high-severity vulnerability with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- CVSS v4: 8.5
- EPSS exploit prediction: 0% (27th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-31831
- Weakness: CWE-77
- Published:
- Last modified:
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 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.
Frequently asked questions
- 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.
- How severe is CVE-2026-40034?
- CVE-2026-40034 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-40034 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-40034?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-40034 have an EU (EUVD) identifier?
- Yes. CVE-2026-40034 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31831.
- When was CVE-2026-40034 published?
- CVE-2026-40034 was published on 2026-05-26 and last updated on 2026-06-17.
References
- https://github.com/GitoxideLabs/gitoxide/commit/6a2e6a436f76c8bbf2487f9967413a51356667a0
- https://github.com/GitoxideLabs/gitoxide/commit/dd5c18d9e526e8de462fa40aa047acd097cfa7dc
- https://github.com/GitoxideLabs/gitoxide/security/advisories/GHSA-f26g-jm89-4g65
- https://red.anthropic.com/2026/cvd/findings/ANT-2026-6SNS6KMP
- https://www.vulncheck.com/advisories/gitoxide-command-injection-via-partial-gitmodules-override-in-gix-submodule
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