The chmd_read_headers function in chmd.c in libmspack before 0.5 does not validate name lengths, which allows remote attackers to cause a denial of service (buffer over-read and application crash) via a crafted CHM file.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.