GHSA-6GCW-W7CP-94G9 comm: lossy UTF-8 conversion silently corrupts non-UTF-8 output

The comm utility in uutils coreutils silently corrupts data by performing lossy UTF-8 conversion on all output lines. The implementation uses String::fromutf8lossy, which replaces invalid UTF-8 byte sequences with the Unicode replacement character U+FFFD. This behavior differs from GNU comm, whic...