RC Between GitHub's Repo Transfer REST API and updateTeamsRepository GraphQL Mutation Results in Covert and Persistent Admin Access Retention

Summary

A race condition in GitHub Enterprise Server allowed an existing admin to maintain permissions on transferred repositories by making a GraphQL mutation to alter repository permissions during the transfer. This vulnerability affected GitHub Enterprise Server version 3.8.0 and above and was fixed in version 3.8.12, 3.9.7, 3.10.4, and 3.11.1.