LilyPond before 2.24 allows attackers to bypass the -dsafe protection mechanism via output-def-lookup or output-def-scope, as demonstrated by dangerous Scheme code in a .ly file that causes arbitrary code execution during conversion to a different file format. NOTE: in 2.24 and later versions, safe mode is removed, and the product no longer tries to block code execution when external files are used.
https://www.mediawiki.org/wiki/Extension:Score/2021_security_advisory
https://tracker.debian.org/news/1249694/accepted-lilypond-2221-1-source-into-unstable/
https://phabricator.wikimedia.org/T259210
https://lilypond.org/download.html
https://gitlab.com/lilypond/lilypond/-/merge_requests/1522
http://lilypond.org/doc/v2.18/Documentation/usage/command_002dline-usage