CVE-2026-3854 Remote code execution via git push option injection in GitHub Enterprise Server
An attacker with push access can achieve remote code execution on GitHub Enterprise Server by injecting metadata into internal service headers via crafted git push options.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-3854?
CVE-2026-3854 is a high-severity command injection vulnerability in Github Enterprise Server, published on 10 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed an attacker with push access to a repository to achieve remote code execution on the instance. During a git push operation, user-supplied push option values were not properly sanitized before being included in internal service headers. Because the internal header format used a delimiter character that could also appear in user input, an attacker could inject additional metadata fields through crafted push option values. This vulnerability was reported via the GitHub Bug Bounty program and has been fixed in GitHub Enterprise Server versions 3.14.25, 3.15.20, 3.16.16, 3.17.13, 3.18.7 and 3.19.4.
Weakness: CWE-77
Which versions are affected by CVE-2026-3854?
It affects 1 product.
Products include Github Enterprise Server.
How do I fix CVE-2026-3854?
No fix has been published for CVE-2026-3854 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-3854 being exploited?
There is no known exploitation of CVE-2026-3854 in the wild and no public exploit code.
Public exploit code: 7 proofs of concept on GitHub.
Other vulnerabilities in Github Enterprise Server
- CVE-2024-4985 Auth bypass in Enterprise Server
- CVE-2022-23739 Missing authorization in GitHub Enterprise Server
- CVE-2022-46255 Improper Limitation of a Pathname to a Restricted Directory in GitHub Enterprise Server leading to RCE
- CVE-2021-22869 Improper access control in GitHub Enterprise Server allows self-hosted runners to execute outside their control group
- CVE-2024-9487 Auth bypass in Enterprise Server
Sources
Also known as GHSA-64fw-jx9p-5j24.