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 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.

The following products are affected by CVE-2026-8034 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-8034.

URL	Resource
https://docs.github.com/en/[email protected]/admin/release-notes#3.16.18
https://docs.github.com/en/[email protected]/admin/release-notes#3.17.15
https://docs.github.com/en/[email protected]/admin/release-notes#3.18.9
https://docs.github.com/en/[email protected]/admin/release-notes#3.19.6
https://docs.github.com/en/[email protected]/admin/release-notes#3.20.2