Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_P
CVE-2026-75101Authorization bypass vulnerability in GitHub Enterprise Server allowed reading of private pull request diffs and patches via repository name collision
Medium 6.0
In plain English
A medium-severity authorization bypass via user-controlled key in Enterprise Server from GitHub. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).
Official description
An authorization bypass vulnerability was identified in GitHub Enterprise Server that allowed any authenticated user of the instance to read the raw diff or patch of pull requests in private repositories without authorization. Access tokens for raw pull request diffs and patches were scoped to the repository name and pull request number rather than to a globally unique repository identifier, so an attacker who created a repository and pull request matching a target's repository name and pull request number could use a token for their own repository to retrieve the private pull request's contents. Exploitation required the attacker to know the target repository's name and a valid pull request number. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.21, 3.18.15, 3.19.12, 3.20.8, and 3.21.6. This vulnerability was reported via the GitHub Bug Bounty program.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| GitHub | Enterprise Server | 3.17.0 – before 3.17.*3.18.0 – before 3.18.*3.19.0 – before 3.19.*3.20.0 – before 3.20.*3.21.0 – before 3.21.* |
Weakness: CWE-639 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
References
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.21 release-notes
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.15 release-notes
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.12 release-notes
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.8 release-notes
- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.6 release-notes