CVE-2026-5512CWE-201

Improper authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository names via mobile upload policy API

Medium · published April 21, 2026

CVSS v4.0
5.3
EPSS
0%
Percentile
41.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
5.3 · MEDIUM
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
EPSS
0.00496 · 41.6th percentile
Weakness
CWE-201 · Insertion of Sensitive Information Into Sent Data
Published
2026-04-21T22:12Z
EPSS history
Timeline
  • 21 APR 22:12Z
    Improper authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository names via mobile upload policy API
    cvelistv5