The PCRE library has just fixed a buffer overflow (related to UTF-8 mode). There are several haskell wrappers for the pcre library. If you use a wrapper for the PCRE library (libpcre) then you may want to upgrade the underlying library. http://pcre.org/news.txt states:

News about PCRE releases ------------------------

Release 7.6 28-Jan-08 ---------------------

The main reason for having this release so soon after 7.5 is because it fixes a potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In addition, the CMake configuration files have been brought up to date.

Cheers, Chris