Control: affects 796184 + kwin Can confirm that. The workaround is to download libkdecorations2-5_5.3.2-1_*deb and libkdecorations2private5_5.3.2-1_*.deb from http://snapshot.debian.org/package/kdecoration/4%3A5.3.2-1/ and install that.
Problem is that it now is build against libstdc++ from this transition: https://release.debian.org/transitions/html/libstdc++6.html It should have never been transitioned to testing.
