A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7, which fixes this issue.
Analyzing vulnerability vectors…