I am trying to find authoritative answer to the following questions:
Is Wicket 1.5.10 the last release there will be and are security fixes being downported to the 1.15 code branch?
On the official distribution site I see there are no new releases of the 1.5 version since Feb.2013 and I can't find anywhere on the Wicket web site statement that clarifies the maintenance plans or policy for the 1.5 version.
Additional info: Wicket 1.5 will be supported until Wicket 7.0.3/4 according to a post from Martin Grigorov on Wicket's Mailing list
So a major release has 2 years life. Actually even more because 1.5.x will be supported until 7.0.3/4 before be moved to security maintenance mode. At least this has been the case with the previous releases.
So i think you have quite some time it will be supported in terms of secuirty.