CVE-2026-14340
mediumpriority · track · 20OT risk · elevatedEPSS 0.004 · 37 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.3–5.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (12)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
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references (18)
External citations — patches, advisories, analysis.
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.20cnnvd
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17cnnvd
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11cnnvd
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8cnnvd
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4cnnvd
- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.2cnnvd
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.20enisa_euvd
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17enisa_euvd
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