Updated procmail packages has been released for CentOS 5 and 6:

CESA-2014:1172 Important CentOS 5 procmail Security Update
CESA-2014:1172 Important CentOS 6 procmail Security Update

CESA-2014:1172 Important CentOS 5 procmail Security Update

CentOS Errata and Security Advisory 2014:1172 Important

Upstream details at : https://rhn.redhat.com/errata/RHSA-2014-1172.html

The following updated files have been uploaded and are currently
syncing to the mirrors: ( sha256sum Filename )

i386:
64e3127ff14a2c32ae52b4c64c846d0fe2d12dbd57b007936b4cd2ecc91812e8 procmail-3.22-17.1.2.el5_10.i386.rpm

x86_64:
bde0079425663379e46a244d850e0bc7e997c8ebe61c677cd5fb7b28e80f8997 procmail-3.22-17.1.2.el5_10.x86_64.rpm

Source:
88bc1b4b7cf9af284bbc8f5f4941edc22e7bd7bb8d48d28359d4cc6f4e782540 procmail-3.22-17.1.2.el5_10.src.rpm

CESA-2014:1172 Important CentOS 6 procmail Security Update

CentOS Errata and Security Advisory 2014:1172 Important

Upstream details at : https://rhn.redhat.com/errata/RHSA-2014-1172.html

The following updated files have been uploaded and are currently
syncing to the mirrors: ( sha256sum Filename )

i386:
a2ff9a08466ca76ebaf1d28890d3d29f51274672a2352689ba4f1150022ec91f procmail-3.22-25.1.el6_5.1.i686.rpm

x86_64:
3060cfa6c9c0ddb002237dc3704ecd888c0b66910bc1fa659a51bdd4fc801962 procmail-3.22-25.1.el6_5.1.x86_64.rpm

Source:
f33eeeb3ef7af0d98af215a1ab8168cf9a728ff2271eaf29abad5786b4929ca1 procmail-3.22-25.1.el6_5.1.src.rpm