# CVE-2026-8606: Server-Side Request Forgery in GitHub Enterprise Server via Advisory Package URL Endpoint

> CVE-2026-8606: Server-Side Request Forgery in GitHub Enterprise Server via Advisory Package URL Endpoint. CVSS 5.9 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-8606
Last updated: 2026-07-23T11:10:00Z

- Published: 2026-05-26 23:59 UTC · Updated: 2026-07-23 11:10 UTC · Assigner: GitHub\_P
- CVSS: 5.9 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS: 0.49%, 42th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-918

## 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.

## Affected vendors and products

- GitHub: Enterprise Server

## Tracked companies

- [GitHub](https://rewindex.com/company/github.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-8606)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-8606)
- [https://docs.github.com/en/enterprise-server@3.16/admin/release-notes\#3.16.19](https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.19)
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes\#3.17.16](https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.16)
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes\#3.18.10](https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.10)
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes\#3.19.7](https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.7)
- [https://docs.github.com/en/enterprise-server@3.20/admin/release-notes\#3.20.3](https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.3)
- [https://docs.github.com/en/enterprise-server@3.21/admin/release-notes\#3.21.1](https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.1)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-8606 · Markdown: https://rewindex.com/cve/CVE-2026-8606.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-8606 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:04:35.138Z