An invalid memory access flaw is present in libyang before v1.0-r1 in the function resolve_feature_value() when an if-feature statement is used inside a list key node, and the feature used is not defined. Applications that use libyang to parse untrusted input yang files may crash.
https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html
https://github.com/CESNET/libyang/issues/723
https://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
https://github.com/CESNET/libyang/commit/32fb4993bc8bb49e93e84016af3c10ea53964be5