I noticed that in current line lrzip version used if slightly buggy and if you still use it consider patching it. Here is a patch for 0.631 version used I created on a whim, basing on patch from their site.

As there is no other place to put that I decided to locate it here. hope it's right place and will help someone.

I think you did not look long?
The first thread in the Slackware forum is called "Requests for -current (14.2 -> 15.0)" and that is where your request should have been posted.
This has nothing to do with "Slackware - Installation" which is the name of this sub-forum.
Also, if you look at the commit history for lrzip, there are many more fixes to the code around that time (a year ago) which do not have a CVE entry but are also fixing crash bugs. So instead of cherry-picking just one commit (which does not make lrzip more stable really) it would be better to use a git snapshot of the latest code.