Is there really an exploit? The advisory says "It is uncertain whether this error is potentially exploitable". On the debian-security mailing list there's a discussion going on and the consensus seems to be that, yes, better update you system but no reports on this bug actually leading to an exploit have been filed.
Anyways, fellow debian users do an apt-get update && apt-get upgrade and are save. The patched version has just been accepted to both stable and unstable (20:41+0200).