An improper authentication vulnerability was identified in GitHub Enterprise Server that allowed an unauthorized actor to modify other users' secret gists by authenticating through an SSH certificate authority. To do so, a user had to know the secret gist's URL. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.9 and was fixed in versions 3.4.18, 3.5.15, 3.6.11, 3.7.8, and 3.8.1. This vulnerability was reported via the GitHub Bug Bounty program.

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed remote code execution when building a GitHub Pages site. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to versions 3.8 and was fixed in versions 3.7.7, 3.6.10, 3.5.14, and 3.4.17. This vulnerability was reported via the GitHub Bug Bounty program.

A code injection vulnerability was identified in GitHub Enterprise Server that allowed setting arbitrary environment variables from a single environment variable value in GitHub Actions when using a Windows based runner. To exploit this vulnerability, an attacker would need existing permission to control the value of environment variables for use with GitHub Actions. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.8.0 and was fixed in versions 3.4.15, 3.5.12, 3.6.8, 3.7.5. This vulnerability was reported via the GitHub Bug Bounty program.