An Improper Neutralization of Input During Web Page Generation vulnerability was identified in GitHub Enterprise Server that allowed attacker controlled HTML to be rendered by the Filter component (search) across GitHub that could be used to exfiltrate sensitive information. An attacker would require permissions to create or modify the names of milestones, issues, pull requests, or similar entities that are rendered in the vulnerable filter/search components. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.19.1, and 3.18.2, 3.17.8, 3.16.11, 3.15.15, and 3.14.20. This vulnerability was reported via the GitHub Bug Bounty program.

A privilege escalation vulnerability was identified in GitHub Enterprise Server that allowed an authenticated Enterprise admin to gain root SSH access to the appliance by exploiting a symlink escape in pre-receive hook environments. By crafting a malicious repository and environment, an attacker could replace system binaries during hook cleanup and execute a payload that adds their own SSH key to the root user’s authorized keys—thereby granting themselves root SSH access to the server. To exploit this vulnerability, the attacker needed to have enterprise admin privileges. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.19, and was fixed in versions 3.14.20, 3.15.15, 3.16.11, 3.17.8, 3.18.2. This vulnerability was reported via the GitHub Bug Bounty program.