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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-4821 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc. (Products Only)
CVSS-B 8.1 HIGH
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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://docs.github.com/en/[email protected]/admin/release-notes#3.14.24 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5 GitHub, Inc. (Products Only)
https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1 GitHub, Inc. (Products Only)

Weakness Enumeration

CWE-ID CWE Name Source
CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') GitHub, Inc. (Products Only)  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-4821
NVD Published Date:
04/21/2026
NVD Last Modified:
04/22/2026
Source:
GitHub, Inc. (Products Only)