CVE-2026-5512

Summary

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.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Additional information

• NVD record
• https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26Advisory
• https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21Advisory
• https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17Advisory
• https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14Advisory
• https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8Advisory
• https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5Advisory
• https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1Advisory