chmd_read_headers in mspack/chmd.c in libmspack before 0.8alpha accepts a filename that has '\0' as its first or second character (such as the "/\0" name).
https://access.redhat.com/errata/RHSA-2019:2049
https://bugs.debian.org/911637
https://github.com/kyz/libmspack/commit/8759da8db6ec9e866cb8eb143313f397f925bb4f
https://lists.debian.org/debian-lts-announce/2018/10/msg00017.html
https://security.gentoo.org/glsa/201903-20
https://usn.ubuntu.com/3814-1/
https://usn.ubuntu.com/3814-2/