CVE-2026-5512

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.

• CWE-201

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

Published

Apr 21, 2026

Last Modified

Jun 17, 2026

Status

Analyzed