Don't get too paranoid about these bulletins. In case anyone has not read it
"Integer overflow in XnViewer (aka XnView) before 1.98.5 allows remote attackers to execute arbitrary code via a crafted file containing PSD record types"
So it should certainly be considered but in the context that.
It is a crafted file, not every psd file. I suppose it depends from where you get your psd files

Maybe convert before opening in xnview.
Applies to xnview before 1.98.5 & the current version is 1.98.8
There was a similar announcement recently for (was it) pcx files which for me is not a file type that I commonly (ever) use.
Finally it still does not apply if you use the RobA's shell-out script which uses png as an intermediate file.
I had a quick search and nothing comes up about XnViewMP which is from the same author.