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.

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History

Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
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.
Title Proxy configuration command injection vulnerability found in GitHub Enterprise Server Management Console configuration API
Weaknesses CWE-78
References
Metrics cvssV4_0

{'score': 8.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_P

Published:

Updated: 2026-04-21T22:12:26.772Z

Reserved: 2026-03-25T13:55:26.048Z

Link: CVE-2026-4821

cve-icon Vulnrichment

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cve-icon NVD

Status : Received

Published: 2026-04-21T23:16:22.037

Modified: 2026-04-21T23:16:22.037

Link: CVE-2026-4821

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses