LZ4 through 1.10.0 allows attackers to cause a denial of service (application crash) or possibly have unspecified other impact when the application processes untrusted LZ4 frames. For example, LZ4F_createCDict_advanced in lib/lz4frame.c mishandles NULL checks.
Maintainers says that this is not a CVE: https://github.com/lz4/lz4/pull/1593#issuecomment-3459207943