In Netwide Assembler (NASM) 2.14rc0, there is a heap-based buffer over-read in the function detoken() in asm/preproc.c that will cause a remote denial of service attack.
https://usn.ubuntu.com/3694-1/
http://repo.or.cz/nasm.git/commit/9b7ee09abfd426b99aa1ea81d19a3b2818eeabf9