Answer in brief
CVE-2026-76851 records a High severity (CVSS 8.8) vulnerability in Server-Side Request Forgery vulnerability in GitHub Enterprise Server allowed remote code execution via network access from pre-receive hooks to internal services. The current sources do not mark it as known exploited. The current feed maps GitHub/Enterprise Server (generic), GitHub/Enterprise Server (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps GitHub/Enterprise Server (generic), GitHub/Enterprise Server (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| GitHub/Enterprise Servergeneric | 3.17.0 || 3.18.0 || 3.19.0 || 3.20.0 || 3.21.0 | Not reported |
| GitHub/Enterprise Servergeneric | >=3.17.0 <=3.17.19 || >=3.18.0 <=3.18.13 || >=3.19.0 <=3.19.10 || >=3.20.0 <=3.20.6 || >=3.21.0 <=3.21.4 | Not reported |
Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
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.
Quoted source text, attributed separately from HOL analysis.