In the remote chance that people here havn't already spotted it (there was 
mention of it on one of the Centos lists yesterday and lots of other 
places), there is likely to be a kernel security update for el-5 really 
soon (el-4 and earlier are not affected).

   https://bugzilla.redhat.com/show_bug.cgi?id=432251

Comment #39 says:

   ... and are finishing up the QA process for Red Hat Enterprise Linux 5.
   We expect this to be completed shortly (pending successful completion of
   testing).  This will be RHSA-2008:0129.

I'm assuming that since this is an urgent security issue they will just be 
adding the trivial upstream patch into kernel -53.1.x rather than waiting 
for -79+ to finish full QA.

  -- Jon