It was only in rolling release/testing/unstable distributions, a pretty small subset of systems in the grand scheme of things, is why I said that. It was introd

It was only in rolling release/testing/unstable distributions, a pretty small subset of systems in the grand scheme of things, is why I said that. It was introduced in February 23 release of xz. This could've been years until discovered. Never use unstable/testing on real servers, that's a bad idea for entirely different reasons.