GitHub Enterprise Auth Bypass on Diff API (up to 3.20)
CVE-2026-9132 Published on June 30, 2026

Missing authorization vulnerability in GitHub Enterprise Server allowed disclosure of private repository contents via the Copilot pull request diff summary endpoint
A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.

NVD

Vulnerability Analysis

CVE-2026-9132 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.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE

Weakness Type

What is an AuthZ Vulnerability?

The software does not perform an authorization check when an actor attempts to access a resource or perform an action.

CVE-2026-9132 has been classified to as an AuthZ vulnerability or weakness.


Products Associated with CVE-2026-9132

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github Enterprise Server
 

Affected Versions

GitHub Enterprise Server: