A Remote Code Execution (RCE) vulnerability was identified in GitHub Enterprise Server that allowed attackers to execute arbitrary code by exploiting the pre-receive hook functionality, potentially leading to privilege escalation and system compromise. The vulnerability involves using dynamically allocated ports that become temporarily available, such as during a hot patch upgrade. This means the vulnerability is only exploitable during specific operational conditions, which limits the attack window. Exploitation required either site administrator permissions to enable and configure pre-receive hooks or a user with permissions to modify repositories containing pre-receive hooks where this functionality was already enabled. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.18 and was fixed in versions 3.17.1, 3.16.4, 3.15.8, 3.14.13, 3.13.16. This vulnerability was reported via the GitHub Bug Bounty program.
Conclusion & alert: CVE-2025-3509 is rated Moderate Risk (57.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.13%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-27 | 2.24% | 2.13% | -0.11% |
| 2 | 2026-05-26 | 2.26% | 2.24% | -0.03% |
| 3 | 2026-02-11 | — | 2.26% | — |
Full EPSS history (14 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.1 | 4.0 | HIGH |
|
— | — | [email protected] |
| 7.2 | 3.1 | HIGH |
|
1.2 | 5.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| github | enterprise_server | < 3.13.16 | cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* |
| github | enterprise_server | >= 3.14.0, < 3.14.13 | cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* |
| github | enterprise_server | >= 3.15.0, < 3.15.8 | cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* |
| github | enterprise_server | >= 3.16.0, < 3.16.4 | cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* |
| github | enterprise_server | >= 3.17.0, < 3.17.1 | cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* |