Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Github | Enterprise Server | < 3.14.26 |
Related Weaknesses (CWE)
References
- https://docs.github.com/en/[email protected]/admin/release-notes#3.14.24Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5Release NotesVendor Advisory
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1Release NotesVendor Advisory
FAQ
What is CVE-2026-4821?
CVE-2026-4821 is a vulnerability with a CVSS score of 7.2 (HIGH). 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 ...
How severe is CVE-2026-4821?
CVE-2026-4821 has been rated HIGH with a CVSS base score of 7.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-4821?
Check the references section above for vendor advisories and patch information. Affected products include: Github Enterprise Server.