SSRF in Github Enterprise Server
CVE-2026-5921
A server-side request forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an attacker to extract sensitive environment variables from the instance through a timing side-channel attack against the notebook r…
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.001 (23.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.9 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L.
Affected products
- Github Enterprise Server — versions 3.14.0, 3.15.0, 3.16.0
- Github Enterprise_server — versions 3.20.0
Weakness classification (CWE)
References
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
- product-cna@github.com (release-notes, Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-5921?
- CVE-2026-5921 is a high-severity vulnerability in Github Enterprise Server, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.9/10. Published 2026-04-21.
- How severe is CVE-2026-5921?
- High severity. CVSS v3 base score is 8.9 out of 10.