What is wrong here? I have this update received via stable-updates not via testing-updates.
I'm not entirely sure. If you look at the history here, it was supposedly pushed automatically, but then it was ejected, whatever this means (devel thread about ejected updates, ticket). So I've just pushed it manually.
Upstream test case for CVE-2019-25013 no longer segfaults. System still boots and core functionality is available.