CVE-2026-14340
An incorrect authorization vulnerability in GitHub Enterprise Server allows issue creation in unrelated public repositories
Description
An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a user-to-server token scoped to a GitHub App installation to perform certain write operations on public repositories outside the token's intended scope. This was possible because the authorization check only verified that the installation had read permissions on the target repository rather than verifying that the token's installation was explicitly granted access to that repository. An attacker who obtained a victim's user-to-server token could create issues, issue comments, commit comments, and private vulnerability reports on any public repository, appearing as the victim user with no indication of the app involvement. This vulnerability was fixed by adding a repository scope check for user-to-server tokens issued by global apps. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.2, 3.20.4, 3.19.8, 3.18.11, 3.17.17, 3.16.20. This vulnerability was reported via the GitHub Bug Bounty program.
INFO
Published Date :
July 1, 2026, 9:03 p.m.
Last Modified :
July 1, 2026, 9:03 p.m.
Remotely Exploit :
Yes !
Source :
GitHub_P
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 82327ea3-741d-41e4-88f8-2cf9e791e760 |
Solution
- Update GitHub Enterprise Server to version 3.21.2 or later.
- Apply security patches for affected versions.
- Review and restrict token scopes.
- Monitor repository access logs.
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