Incorrect Auth in GitHub Enterprise Server <3.22 via User-to-Server Tokens
CVE-2026-14340 Published on July 1, 2026
An incorrect authorization vulnerability in GitHub Enterprise Server allows issue creation in unrelated public repositories
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.
Vulnerability Analysis
CVE-2026-14340 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is an AuthZ Vulnerability?
The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
CVE-2026-14340 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-14340
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Affected Versions
GitHub Enterprise Server:- Version 3.16.0, <= 3.16.19 is affected.
- Version 3.17.0, <= 3.17.16 is affected.
- Version 3.18.0, <= 3.18.10 is affected.
- Version 3.19.0, <= 3.19.7 is affected.
- Version 3.20.0, <= 3.20.3 is affected.
- Version 3.21.0, <= 3.21.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.