CVE-2026-76851

HIGH CVSS 4.0: 7.7 EPSS 0.51%
Updated Sep 08, 2026
GitHub
Parameter Value
CVSS 7.7 (HIGH)
Affected Versions 3.18.0 — 3.21.5
Fixed In 3.17.20
Type CWE-918 (Server-Side Request Forgery (SSRF))
Vendor GitHub
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v4.0

Vulnerable Products 5

Configuration From (including) Up to (excluding)
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.17.20
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.18.0 3.18.14
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.19.0 3.19.11
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.20.0 3.20.7
Github Enterprise_Server
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
3.21.0 3.21.5