A use-after-free vulnerability exists in the NMR::COpcPackageReader::releaseZIP() functionality of 3MF Consortium lib3mf 2.0.0. A specially crafted 3MF file can lead to code execution. An attacker can provide a malicious file to trigger this vulnerability (CVE-2021-21772).
A new package 'act' is introduced to build newer version of lib3mf.
Also, openscad is rebuilt against this updated library.