8.1
High
CVE-2026-4821 An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed…
Description
An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed an authenticated Management Console administrator to execute arbitrary OS commands via shell metacharacter injection in proxy configuration fields such as http_proxy. Exploitation of this vulnerability required access to the GitHub Enterprise Server instance and administrator privileges to the Management Console. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Enterprise Server 3.20 | 3.20.0 → < 3.20.1 | 3.20.1 |
| Enterprise Server 3.19 | 3.19.0 → 3.19.4 | No fix stated |
| Enterprise Server 3.18 | 3.18.0 → 3.18.7 | No fix stated |
| Enterprise Server 3.17 | 3.17.0 → 3.17.13 | No fix stated |
| Enterprise Server 3.16 | 3.16.0 → 3.16.16 | No fix stated |
| Enterprise Server 3.15 | 3.15.0 → 3.15.20 | No fix stated |
| Enterprise Server 3.14 | 3.14.0 → 3.14.25 | No fix stated |
Other CVEs of Enterprise Server
The 94 CVEs of Enterprise Server →
CVE-2026-118237
Out-of-bounds read vulnerability in GitHub Enterprise Server allowed disclosure of process memory in the Git service
5.3
Medium
CVE-2026-110288
Cross-site request forgery vulnerability in GitHub Enterprise Server allowed deletion of stored ChatOps configuration through the Management Console
5.3
Medium
CVE-2026-104608
Use-after-free vulnerability in GitHub Enterprise Server allowed remote code execution in the Git service
7.7
High
CVE-2026-96890
A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed a…
8.7
High