CVE-2026-76851
Server-Side Request Forgery vulnerability in GitHub Enterprise Server allowed remote code execution via network access from pre-receive hooks to internal services
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.
INFO
Published Date :
Sept. 1, 2026, 10:17 p.m.
Last Modified :
Sept. 1, 2026, 10:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | 82327ea3-741d-41e4-88f8-2cf9e791e760 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update GitHub Enterprise Server to version 3.17.20 or later.
- Ensure pre-receive hook networking is disabled if not needed.
- Restrict pre-receive hook access to authorized administrators.
- Review and audit pre-receive hook configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-76851.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-76851 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-76851
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-76851 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-76851 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 01, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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 Added CWE CWE-918 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/76xxx/CVE-2026-76851.json">CVE-2026-76851</a> Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.20 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.14 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.11 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.7 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.5