CVE-2026-8606 Server-Side Request Forgery in GitHub Enterprise Server via Advisory Package URL Endpoint
Attackers can exploit SSRF in GitHub Enterprise Server to infer sensitive environment variables via internal service requests, requiring GitHub Packages to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-8606?
CVE-2026-8606 is a high-severity server-side request forgery vulnerability in Github Enterprise Server, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an attacker to cause the server to issue HTTP requests to internal services via the security advisories package lookup feature. By directing requests to an internal management service and measuring response timing, an attacker could infer the values of sensitive environment variables, including signing secrets and private keys. Exploitation required GitHub Packages to be enabled; on instances not running in private mode the vulnerability was exploitable without authentication, otherwise any authenticated user could exploit it. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21.1 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, 3.17.16, and 3.16.19. This vulnerability was reported via the GitHub Bug Bounty program.
Weakness: CWE-918
Which versions are affected by CVE-2026-8606?
It affects 1 product.
Products include Github Enterprise Server.
How do I fix CVE-2026-8606?
No fix has been published for CVE-2026-8606 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-8606 being exploited?
There is no known exploitation of CVE-2026-8606 in the wild and no public exploit code.
Other vulnerabilities in Github Enterprise Server
- CVE-2024-4985 Auth bypass in Enterprise Server
- CVE-2022-23739 Missing authorization in GitHub Enterprise Server
- CVE-2022-46255 Improper Limitation of a Pathname to a Restricted Directory in GitHub Enterprise Server leading to RCE
- CVE-2021-22869 Improper access control in GitHub Enterprise Server allows self-hosted runners to execute outside their control group
- CVE-2024-9487 Auth bypass in Enterprise Server
Sources
Also known as GHSA-3w49-fq5g-g3q6.