CVE catalog
CVE-2026-8034
A server-side request forgery (SSRF) vulnerability was identified in the GitHub Enterprise Server notebook viewer that allowed an attacker to access internal services by exploiting URL parser confusio
- Severity
- High · CVSS 7.9
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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 - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.52% · Oct 25, 2026
A server-side request forgery (SSRF) vulnerability was identified in the GitHub Enterprise Server notebook viewer that allowed an attacker to access internal services by exploiting URL parser confusion between the validation layer and the HTTP request library. The hostname validation used a different URL parser than the request library, enabling a crafted URL to pass validation while directing the request to an unintended host. Exploitation required network access to the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.16.18, 3.17.15, 3.18.9, 3.19.6, and 3.20.2. This vulnerability was reported via the GitHub Bug Bounty program.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | enterprise_server | Not reported | 3.16.18 | fixed |
| Cpe | enterprise_server | Not reported | 3.17.15 | fixed |
| Cpe | enterprise_server | Not reported | 3.18.9 | fixed |
| Cpe | enterprise_server | Not reported | 3.19.6 | fixed |
| Cpe | enterprise_server | Not reported | 3.20.2 | fixed |
| Cpe | enterprise_server | Not reported | 3.20.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | enterprise_server | cpe | Not reported | 3.16.18 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.17.15 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.18.9 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.19.6 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.20.2 | Not reported | Not reported | Not reported |
| Cpe | enterprise_server | cpe | Not reported | 3.20.2 | Not reported | NVD-CVE-2026-8034 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed:
References
- [https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18]
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15]
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9]
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6]
- [https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-8034]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1432.json]
[CERT-Bund public advisories] · [FIRST EPSS] · [National Vulnerability Database (NVD)]