CVE-2026-5512: An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated…
CVE-2026-5512 · Severity: medium · CVSS 4.3 · Published 2026-04-21
An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to determine the names of private repositories by their numeric ID. The mobile upload policy API endpoint did not perform an early authorization check, and validation error messages included the full repository name for repositories the caller did not have access to. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
No. Junglewise Threat Intelligence has no report of CVE-2026-5512 being exploited in the wild.
How severe is CVE-2026-5512?
Medium severity, with a CVSS score of 4.3, published 21 April 2026.
Which products and versions are affected?
GitHub Enterprise Server. The advisory does not name versions.
Is there a fix for CVE-2026-5512?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-5512?
Check whether you run GitHub Enterprise Server. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.