# 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.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Mar 2026
- **Updated:** 29 Apr 2026
- **Also known as:** GHSA-64fw-jx9p-5j24

## 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 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-3854?

It affects 1 product.


Products: 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.

## 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:

- https://github.com/royaleybovich/CVE-2026-3854-lab (github_poc): https://github.com/royaleybovich/CVE-2026-3854-lab
- GitHub RCE via X-Stat Push Option Injection (github_poc): https://github.com/lysophavin18/CVE-2026-3854-PoC
- https://github.com/5kr1pt/CVE-2026-3854 (github_poc): https://github.com/5kr1pt/CVE-2026-3854
- Details about CVE-2026-3854 (github_poc): https://github.com/LACHHAB-Anas/Exploit_CVE-2026-3854
- CVE-2026-3854 patch bypass testing (github_poc): https://github.com/simondankelmann/cve-2026-3854-test
-  GHES CVE Scanner — Defensive security tool for detecting CVE-2026-3854 (Git      Push RCE) and CVE-2026-4821 (Management Console proxy injection) in GitHub   Enterprise Server. Zero external dependencies, Python 3.8+.       (github_poc): https://github.com/isagoakira/ghes-cve-scanner

## Other vulnerabilities in Github Enterprise Server

- [CVE-2024-4985](https://insights.sbomify.com/CVE-2024-4985/): Auth bypass in Enterprise Server (critical 10.0)
- [CVE-2022-23739](https://insights.sbomify.com/CVE-2022-23739/): Missing authorization in GitHub Enterprise Server (critical 9.8)
- [CVE-2022-46255](https://insights.sbomify.com/CVE-2022-46255/): Improper Limitation of a Pathname to a Restricted Directory in GitHub Enterprise Server leading to RCE (critical 9.8)
- [CVE-2021-22869](https://insights.sbomify.com/CVE-2021-22869/): Improper access control in GitHub Enterprise Server allows self-hosted runners to execute outside their control group (critical 9.8)
- [CVE-2024-9487](https://insights.sbomify.com/CVE-2024-9487/): Auth bypass in Enterprise Server (critical 9.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3854 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-3854 in the wild and no public exploit code.

Affected product: Github Enterprise Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3854/ (Markdown: https://insights.sbomify.com/CVE-2026-3854/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3854
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3854
- OSV: https://osv.dev/vulnerability/CVE-2026-3854

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3854/
Summaries are generated and may contain mistakes; the official description above is the record.