CVE-2026-8606: Server-Side Request Forgery in GitHub Enterprise Server via Advisory Package URL Endpoint
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.21.1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.20.3 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.19.7 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.18.10 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.17.16 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.16.19
Event History
Frequently Asked Questions
What is the severity of CVE-2026-8606?
CVE-2026-8606 has a severity rating of high, with a CVSS score of 7.
What is CVE-2026-8606?
CVE-2026-8606 is a Server-Side Request Forgery (SSRF) vulnerability in GitHub Enterprise Server that could allow an attacker to issue HTTP requests to internal services.
How do I fix CVE-2026-8606?
To fix CVE-2026-8606, update GitHub Enterprise Server to the latest version that contains the patch for this vulnerability.
What systems are affected by CVE-2026-8606?
CVE-2026-8606 affects versions of GitHub Enterprise Server prior to the release that includes the fix for the SSRF vulnerability.
How can CVE-2026-8606 impact my organization's security?
CVE-2026-8606 could potentially allow attackers to access sensitive internal services, thereby compromising the security of your organization's infrastructure.