mspack/lzxd.c in libmspack 0.5alpha, as used in ClamAV 0.99.2, allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted CHM file.
The wwunpack function in libclamav/wwunpack.c in ClamAV 0.99.2 allows remote attackers to cause a denial of service (use-after-free) via a crafted PE file with WWPack compression.