Updated tzdata packages are available for both CentOS 5 and 6:

CEEA-2014:0338 CentOS 5 tzdata Update
CEEA-2014:0338 CentOS 6 tzdata Update

CEEA-2014:0338 CentOS 5 tzdata Update

CentOS Errata and Enhancement Advisory 2014:0338

Upstream details at : https://rhn.redhat.com/errata/RHEA-2014-0338.html

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

i386:
fea2b344366e13afd381523e1454c27f900c238fd3b1a024387adc23b67fc95c tzdata-2014b-1.el5.i386.rpm
111912ddda8cb09f7f4f9e3bdadf1db07cc05c8d7f1a2cf6850cda325c07aa4a tzdata-java-2014b-1.el5.i386.rpm

x86_64:
bcd3c2ff7723a3a6c8fba77ec565bd21b78ffdc9608a66346b3610df2a39e526 tzdata-2014b-1.el5.x86_64.rpm
547f704bd86f02574edb95ad4b3fdd0f43af4298325086904404e967f5f167bb tzdata-java-2014b-1.el5.x86_64.rpm

Source:
008716443c19df9ad5dcacc05faeede34a9fea7a82ad61db88477af9c06a4442 tzdata-2014b-1.el5.src.rpm

CEEA-2014:0338 CentOS 6 tzdata Update

CentOS Errata and Enhancement Advisory 2014:0338

Upstream details at : https://rhn.redhat.com/errata/RHEA-2014-0338.html

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

i386:
e838993fa935111ebd827d74c2566ed6faf6648f17832521c7bf5f94c6f0a478 tzdata-2014b-1.el6.noarch.rpm
51ce6a2ca48acefe8d22d314c8b38f3085fc00df14f4a131d76b520e3dbad837 tzdata-java-2014b-1.el6.noarch.rpm

x86_64:
e838993fa935111ebd827d74c2566ed6faf6648f17832521c7bf5f94c6f0a478 tzdata-2014b-1.el6.noarch.rpm
51ce6a2ca48acefe8d22d314c8b38f3085fc00df14f4a131d76b520e3dbad837 tzdata-java-2014b-1.el6.noarch.rpm

Source:
67517de3e491ca15b1e0ca3cd3aff6b7fc028c7b1ebabcc0a4c30e967bc0e0b1 tzdata-2014b-1.el6.src.rpm