CVE intelligence and bounded remediation

CVE-2026-8606 — Github Enterprise Server security vulnerability

High CVSS 7

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.

Severity
High
CVSS
7 (4.0)
Published
2026-05-27
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-918

Affected products

  • github / enterprise_server
  • github / enterprise_server / 3.21.0

Showing 2 representative product identities from 6 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.