A double-free is present in libyang before v1.0-r1 in the function yyparse() when an empty description is used. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html
https://github.com/CESNET/libyang/issues/742
https://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
https://github.com/CESNET/libyang/commit/d9feacc4a590d35dbc1af21caf9080008b4450ed