CVE-2026-57455 Vim: Stack out-of-bounds write in `spell_soundfold_sofo()` via an over-length `soundfold()` argument

Vim is an open source, command line text editor. Prior to 9.2.0698, the single-byte branch of spellsoundfoldsofo in src/spell.c translates a word through a spell file's SOFO sound-folding byte map into a caller-owned result buffer. Its copy loop advances the output index ri with no upper bound an...