🛡️ CVE-2026-4821 — enterprise-server

🟠 CVSS 7.2 — High ✅ No Known Exploit CWE-78 NVD
7.2
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs administrative privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2026-4821 is classified as CWE-78: OS Command Injection. Untrusted input reaches a shell command without neutralisation, so an attacker can run arbitrary operating system commands.

Affected software

CVE-2026-4821 is recorded against 2 packages.

  • enterprise-server
  • unknown

Timeline and source

Published on 21 April 2026 and last revised on 29 April 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

docs.github.com
docs.github.com
docs.github.com
docs.github.com
docs.github.com
docs.github.com
docs.github.com

Details

Severity HIGH
CVSS Score 7.2
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE CWE-78
Public Exploit ✅ No
Source NVD
Published 2026-04-21
Updated 2026-06-11
Modified 2026-04-29
Fix URL N/A

Affected Packages

Software From version Fixed in
enterprise-server — —
unknown — —

Similar Threats

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