Is there a way to undo an edit that one has suggested before it has been reviewed? I realized that my edit on this answer was wrong.
As far as I know, this is currently not possible. As a workaround you can consider to leave a comment on the post, indicating that your edit should not be approved. This could help the reviewers to make the correct decisions, or if ever it still gets approved, help somebody clean up the issue.
If you think the feature you ask about would be useful and you want to see it implemented, you can vote for feature-requests on meta.SE: