CVE-2026-76851

Vulnerability Description

A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed remote code execution on the instance. Insufficient network isolation allowed malicious pre-receive hook code to impersonate an internal service and redirect trusted internal requests to a privileged service, leading to elevated code execution. Exploitation required pre-receive hook networking to be enabled and either site administrator privileges or write access to a repository containing a configured pre-receive hook. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.20, 3.18.14, 3.19.11, 3.20.7, and 3.21.5. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS Score

Affected Products

Related Weaknesses (CWE)

References

• https://docs.github.com/en/[email protected]/admin/release-notes#3.17.20Release NotesVendor Advisory
• https://docs.github.com/en/[email protected]/admin/release-notes#3.18.14Release NotesVendor Advisory
• https://docs.github.com/en/[email protected]/admin/release-notes#3.19.11Release NotesVendor Advisory
• https://docs.github.com/en/[email protected]/admin/release-notes#3.20.7Release NotesVendor Advisory
• https://docs.github.com/en/[email protected]/admin/release-notes#3.21.5Release NotesVendor Advisory