The git hook feature in Gogs 0.5.5 through 0.12.2 allows for authenticated remote code execution. There can be a privilege escalation if access to this hook feature is granted to a user who does not have administrative privileges. NOTE: because this is mentioned in the documentation but not in the UI, it could be considered a "Product UI does not Warn User of Unsafe Actions" issue.
Open redirect vulnerability in Gogs before 0.12 allows remote attackers to redirect users to arbitrary websites and conduct phishing attacks via an initial /\ substring in the user/login redirect_to parameter, related to the function isValidRedirect in routes/user/auth.go.