CVE-2026-4821

Summary

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 Software

VendorProductVersion RangeStatus
GitHubEnterprise Server3.20.0 < 3.20.1affected
GitHubEnterprise Server3.19.0 <= 3.19.4affected
GitHubEnterprise Server3.18.0 <= 3.18.7affected
GitHubEnterprise Server3.17.0 <= 3.17.13affected
GitHubEnterprise Server3.16.0 <= 3.16.16affected
GitHubEnterprise Server3.15.0 <= 3.15.20affected
GitHubEnterprise Server3.14.0 <= 3.14.25affected

Weaknesses

  • CWE-78: CWE-78 Improper neutralization of special elements used in an OS command ('OS command injection')

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References