cut: -s ignored in -z -d '' newline-delimiter mode

cut routes -z -d '' through a special newline-delimiter path that ignores the -s only-delimited flag, emitting whole undelimited records (plus NUL) that should be suppressed. Pipelines relying on cut -s to drop undelimited records process data that should be filtered.

printf 'abc' | cut -z -d '' -s -f 1 | od -An -tx1   # GNU: no output ; uutils: 61 62 63 00

Zellic private finding (zellic-ext/coreutils-private PR #102). Reported in the Zellic uutils coreutils Program Security Assessment (for Canonical, Jan 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242.