Proxy configuration command injection vulnerability found in GitHub Enterprise Server Management Console configuration API

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-4821
StatePUBLISHED
AssignerGitHub_P
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-21 23:16:22 UTC
Updated2026-04-29 12:36:27 UTC
DescriptionAn 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.

Risk And Classification

Primary CVSS: v4.0 8.1 HIGH from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000140000 probability, percentile 0.025500000 (date 2026-04-22)

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

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.1HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/C...
4.0CNACVSS8.1HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
3.1[email protected]Primary7.2HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
High
User Interaction
None
Confidentiality
None
Integrity
High
Availability
None
Sub Conf.
None
Sub Integrity
High
Sub Availability
None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Github Enterprise Server All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA GitHub Enterprise Server affected 3.20.0 3.20.1 semver Not specified
CNA GitHub Enterprise Server affected 3.19.0 3.19.4 semver Not specified
CNA GitHub Enterprise Server affected 3.18.0 3.18.7 semver Not specified
CNA GitHub Enterprise Server affected 3.17.0 3.17.13 semver Not specified
CNA GitHub Enterprise Server affected 3.16.0 3.16.16 semver Not specified
CNA GitHub Enterprise Server affected 3.15.0 3.15.20 semver Not specified
CNA GitHub Enterprise Server affected 3.14.0 3.14.25 semver Not specified

References

ReferenceSourceLinkTags
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Seokchan Yoon (en)

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