Server-side request forgery in GitHub Enterprise Server
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.
Summary
A server-side request forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause the Manage API to send crafted outbound requests to an attacker-controlled host. An unauthenticated endpoint parsed an attacker-supplied cluster configuration and issued gateway-to-agent requests whose HMAC authenticated only a timestamp, not the request path or body. An attacker positioned to intercept the outbound request could capture this token and replay it against privileged management agent endpoints. High-availability deployments were not affected due to a topology restriction. This vulnerability affected GitHub Enterprise Server releases in the 3.17, 3.18, 3.19, 3.20, and 3.21 series and was fixed in versions 3.17.21, 3.18.15, 3.19.12, 3.20.8, and 3.21.6. This vulnerability was reported via the GitHub Bug Bounty program.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| GitHub | Enterprise Server | 3.17.0 and later; 3.18.0 and later; 3.19.0 and later; 3.20.0 and later; 3.21.0 and later | — | No fix listed | CNA |
- Enterprise Server VendorGitHub Affected 3.17.0 and later; 3.18.0 and later; 3.19.0 and later; 3.20.0 and later; 3.21.0 and later Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* | before 3.17.19; 3.18.0 to before 3.18.13; 3.19.0 to before 3.19.10; 3.20.0 to before 3.20.6; 3.21.0 to before 3.21.4 | Vulnerable | GitHub |
- cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* Versions before 3.17.19; 3.18.0 to before 3.18.13; 3.19.0 to before 3.19.10; 3.20.0 to before 3.20.6; 3.21.0 to before 3.21.4 Vulnerable ·GitHub
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18730
- 2026-10-03 Alias added: GHSA-xh7g-7v3x-h73p
References
Other 5
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.21
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.15
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.12
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.8
- https://docs.github.com/en/[email protected]/admin/release-notes#3.21.6
More GitHub Enterprise Server vulnerabilities
- TI-2024-04632 An authentication bypass vulnerability was present in the GitHub Enterprise Server (GHES)… CVSS 4.0CRITICAL 10.0
- TI-2024-00181 Unsafe Reflection in Github Enterprise Server leading to Command Injection CVSS 3.1CRITICAL 9.8
- TI-2024-00466 Privilege Escalation by Code Injection in the Management Console in GitHub Enterprise Server CVSS 3.1HIGH 8.8
- TI-2026-03340 Remote code execution via git push option injection in GitHub Enterprise Server CVSS 4.0HIGH 8.7
- TI-2024-08804 Improper signature verification in GitHub Enterprise Server CVSS 4.0CRITICAL 9.5
- TI-2026-08177 Server-side request forgery in GitHub Enterprise Server CVSS 4.0CRITICAL 9.2
Sources
- CVE-2026-18730 · CVE Program
- CVE-2026-18730 · NVD
- FIRST EPSS
- GHSA-xh7g-7v3x-h73p · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences