Sagi Tzadik

Researcher fromWiz
#1847of 56,330
132.6Total CVSS
Vulnerabilities · 16
Medium
2
High
11
Critical
3
PT-2026-24344
9.0
2026-03-04
Github · Github Enterprise Server · CVE-2026-3854
**Name of the Vulnerable Software and Affected Versions** GitHub Enterprise Server versions prior to 3.14.25 GitHub Enterprise Server versions prior to 3.15.20 GitHub Enterprise Server versions prior to 3.16.16 GitHub Enterprise Server versions prior to 3.17.13 GitHub Enterprise Server versions prior to 3.18.8 GitHub Enterprise Server versions prior to 3.19.4 GitHub Enterprise Server versions prior to 3.20.0 **Description** An improper neutralization of special elements allows an authenticated attacker with push access to a repository to achieve remote code execution (RCE) on the instance. During a `git push` operation, user-supplied push option values are not properly sanitized before being included in internal service headers. Because the internal header format uses a delimiter character (semicolon) that can also appear in user input, an attacker can inject additional metadata fields. Technical exploitation involves a chain of injections within the `X-Stat` header to bypass sandboxing and execute arbitrary code via pre-receive hooks. Specifically, attackers can manipulate variables such as `rails env` to escape the sandbox, `custom hooks dir` to control hook resolution, and `repo pre receive hooks` to execute binaries like `/bin/bash`. On GitHub Enterprise Server, this can lead to full server compromise, including access to all hosted repositories and internal secrets. On shared infrastructure, it could allow cross-tenant exposure to millions of private repositories. It is estimated that approximately 88% of reachable GitHub Enterprise Server instances remained unpatched at the time of public disclosure. **Recommendations** Upgrade GitHub Enterprise Server to version 3.14.25 or newer. Upgrade GitHub Enterprise Server to version 3.15.20 or newer. Upgrade GitHub Enterprise Server to version 3.16.16 or newer. Upgrade GitHub Enterprise Server to version 3.17.13 or newer. Upgrade GitHub Enterprise Server to version 3.18.8 or newer. Upgrade GitHub Enterprise Server to version 3.19.4 or newer. Upgrade GitHub Enterprise Server to version 3.20.0 or newer. As a temporary mitigation, avoid using `git push` with custom push options (the `-o` flag) until the system is upgraded.