http://www.securitytracker.com/alerts/2005/Aug/1014744.html
Exim 4.52 and snapshot 20050802 contains PCRE 6.0.
According to the alert, only "Applications that parse untrusted regular
expressions may be vulnerable." Exim does not do that by default, AFAIK,
but there may be a few setups allowing that, e.g. user specified filters
with regex.
So is Exim affected?