CVE-2026-5512 MEDIUM

CVE-2026-5512: Improper authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository names via mobile upload policy API

Vendor Github
Product Enterprise Server
Weakness CWE-201
Published April 21, 2026
Last update April 22, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 21, 2026 CVE published
April 22, 2026 Record updated