An XML signature wrapping vulnerability was present in GitHub Enterprise Server (GHES) when using SAML authentication with specific identity providers utilizing publicly exposed signed federation metadata XML. This vulnerability allowed an attacker with direct network access to GitHub Enterprise Server to forge a SAML response to provision and/or gain access to a user with site administrator privileges. Exploitation of this vulnerability would allow unauthorized access to the instance without requiring prior authentication. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.14 and was fixed in versions 3.13.3, 3.12.8, 3.11.14, and 3.10.16. This vulnerability was reported via the GitHub Bug Bounty program.