7.0
HIGH CVSS 4.0
CVE-2026-8606
Server-Side Request Forgery in GitHub Enterprise Server via Advisory Package URL Endpoint
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.

INFO

Published Date :

May 27, 2026, 12:16 a.m.

Last Modified :

May 27, 2026, 12:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-8606 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 82327ea3-741d-41e4-88f8-2cf9e791e760
CVSS 4.0 HIGH [email protected]
Solution
Update GitHub Enterprise Server to the latest patched version to fix SSRF.
  • Update GitHub Enterprise Server to 3.21.1 or later.
  • Apply the specific patch version for your release.
  • Ensure GitHub Packages is configured securely.
  • Restrict access to internal management services.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-8606 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-8606 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-8606 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-8606 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 27, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N/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
    Added CWE CWE-918
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.16.19
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.16
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.10
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.7
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.3
    Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.1
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.