An issue was discovered in mspack/chmd.c in libmspack before 0.7alpha. There is an off-by-one error in the TOLOWER() macro for CHM decompression.
www.openwall.com/lists/oss-security/2018/07/26/1
www.securitytracker.com/id/1041410
access.redhat.com/errata/RHSA-2018:3327
access.redhat.com/errata/RHSA-2018:3505
bugs.debian.org/904800
github.com/kyz/libmspack/commit/4fd9ccaa54e1aebde1e4b95fb0163b699fd7bcc8
lists.debian.org/debian-lts-announce/2018/08/msg00007.html
security.gentoo.org/glsa/201903-20
usn.ubuntu.com/3728-1/
usn.ubuntu.com/3728-2/
usn.ubuntu.com/3728-3/
usn.ubuntu.com/3789-2/
www.debian.org/security/2018/dsa-4260