We currently have two recent versions, one in the 6.x line and one in the 7.x line. Both are considered stable.
Since we cannot switch to the 7.x version anytime soon, but security updates are available for the 6.x version, the message “Security update available” should only be displayed if not all security patches for the 6.x version have been installed.

This leads to uncertainty and unease among users, as this gives the impression that LimeSurvey is being operated with security vulnerabilities, while at the same time handling sensitive data (surveys).