GitPython versions prior to 3.2.0 contain a Regular Expression Denial of Service (ReDoS) vulnerability in the Actor.name_email_regex pattern used to parse commit author and committer metadata. The vulnerable regex causes catastrophic backtracking when processing a commit with an author or committer field containing a long string with an unterminated '<' character. This leads to quadratic CPU time growth proportional to input length, resulting in severe performance degradation and potential denial of service in any GitPython API call accessing commit author or committer information.