GitHub Enterprise Server security vulnerabilities

GitHub Enterprise Server is an open-source application developed by GitHub in the United States. It provides a scalable and easy-to-manage platform by allowing users to set their GitHub instances as virtual devices. Prior to version 3.20 of GitHub Enterprise Server, there were security...

CVE-2026-3854: Improper Neutralization of Special Elements used in a Command

An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed an attacker with push access to a repository to achieve remote code execution on the instance. During a git push operation, user-supplied push option values were not properly...

CVE-2026-3306: Authorization Bypass Through User-Controlled Key

An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed a user with read access to a repository and write access to a project to modify issue and pull request metadata through the project. When adding an item to a project that already existed, column value...

CVE-2026-2266: Improper Neutralization of Input During Web Page Generation

An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed DOM-based cross-site scripting via task list content. The task list content extraction logic did not properly re-encode browser-decoded text nodes before rendering, allowing user-supplied HTM...

CVE-2026-3582: Missing Authorization

An Incorrect Authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with a classic personal access token PAT lacking the repo scope to retrieve issues and commits from private and internal repositories via the search REST API endpoints. The user...

GitHub: OAuth redirect uri validation bypass for :proxima_first_party_sync apps

A vulnerability was identified in GitHub Enterprise Server that allowed an attacker to bypass OAuth redirect URI validation. The vulnerability was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. The vulnerability was reported through the GitHub Bug Bounty program...

PT-2026-24344

Name of the Vulnerable Software and Affected Versions GitHub Enterprise Server versions prior to 3.14.25 GitHub Enterprise Server versions prior to 3.15.20 GitHub Enterprise Server versions prior to 3.16.16 GitHub Enterprise Server versions prior to 3.17.13 GitHub Enterprise Server versions prior...

Vulnerabilities fixed in GitHub Enterprise Server

GitHub has fixed vulnerabilities in GitHub Enterprise Server Specifically for versions before 3.20, 3.19.2, 3.18.5 and 3.17.11. The first vulnerability concerns an authorization issue that allowed attackers to merge unauthorized pull-requests into repositories that provide fork support. The secon...

CVE-2026-1355

A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration...

CVE-2026-1999

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enableautomerge mutation for pull requests. This issue only affect...

CVE-2026-0573

An URL redirection vulnerability was identified in GitHub Enterprise Server that allowed attacker-controlled redirects to leak sensitive authorization tokens. The repositorypages API insecurely followed HTTP redirects when fetching artifact URLs, preserving the authorization header containing a...

CVE-2026-1999

A Server-Side Request Forgery SSRF vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to access internal services bound to loopback or unspecified addresses, potentially disrupting background job processing, accessing administrative endpoints, metrics, and...

CVE-2026-1999

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enableautomerge mutation for pull requests. This issue only affect...

CVE-2026-1355

A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration...

CVE-2026-1355

A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration...

CVE-2026-0573

An URL redirection vulnerability was identified in GitHub Enterprise Server that allowed attacker-controlled redirects to leak sensitive authorization tokens. The repositorypages API insecurely followed HTTP redirects when fetching artifact URLs, preserving the authorization header containing a...

CVE-2026-0573

An URL redirection vulnerability was identified in GitHub Enterprise Server that allowed attacker-controlled redirects to leak sensitive authorization tokens. The repositorypages API insecurely followed HTTP redirects when fetching artifact URLs, preserving the authorization header containing a...

CVE-2026-1999 Incorrect Authorization vulnerability was identified in GitHub Enterprise Server that allowed unauthorized merging of pull requests

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enableautomerge mutation for pull requests. This issue only affect...

CVE-2026-1999

CVE-2026-1999 affects GitHub Enterprise Server and is an incorrect authorization vulnerability in the enable_auto_merge mutation for pull requests. An attacker could merge their own PR into a repository without push access under specific conditions: the repository must allow forking, a clean PR s...

CVE-2026-1999

A Server-Side Request Forgery SSRF vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to access internal services bound to loopback or unspecified addresses, potentially disrupting background job processing, accessing administrative endpoints, metrics, and...