Jenkins Bitbucket Branch Source Plugin 886.v44cf5e4ecec5 and earlier prints the Bitbucket OAuth access token as part of the Bitbucket URL in the build log in some cases.
Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers. Different log files may be produced and stored for: