You probably know this, but here is is none the less.
I'd like to add another program to the list of those which use xpdf: pdfTeX,
(which can be used as "pdfnup" [cf. psnup for ps] program).

http://www.mandrakesoft.com/security/advisories?name=MDKSA-2004:113

Chris Evans discovered numerous vulnerabilities in the xpdf package:

Multiple integer overflow issues affecting xpdf-2.0 and xpdf-3.0. Also programs
like cups which have embedded versions of xpdf. These can result in writing an
arbitrary byte to an attacker controlled location which probably could lead to
arbitrary code execution. (CAN-2004-0888)

Multiple integer overflow issues affecting xpdf-3.0 only. These can result in
DoS or possibly arbitrary code execution. (CAN-2004-0889)

Chris also discovered issues with infinite loop logic error affecting xpdf-3.0 only.