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

CEBA-2014:0295 CentOS 5 tzdata Update
CEBA-2014:0295 CentOS 6 tzdata Update

CEBA-2014:0295 CentOS 5 tzdata Update

CentOS Errata and Bugfix Advisory 2014:0295

Upstream details at : https://rhn.redhat.com/errata/RHBA-2014-0295.html

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

i386:
63c8e2037b4044cb3388933645e026657b78bb3b41efef7bf5a6f7d767be76f4 tzdata-2014a-1.el5.i386.rpm
c1d3a1d85b681cd0198dabb57f135ec6c09a9776f7053a49512f34823c8eceae tzdata-java-2014a-1.el5.i386.rpm

x86_64:
782c581842da4645a443a834a7964ce0f7603618692af3fef9eaa9a6a926fc0d tzdata-2014a-1.el5.x86_64.rpm
7c5057f69c68db6ea80654fcf7cb1b2e622189adb20be992f3710b58df803119 tzdata-java-2014a-1.el5.x86_64.rpm

Source:
645f11eb0a71e16c7d2f7ea08781f57309bdd4cda0580e5aaedc4c6dd6699fa4 tzdata-2014a-1.el5.src.rpm

CEBA-2014:0295 CentOS 6 tzdata Update

CentOS Errata and Bugfix Advisory 2014:0295

Upstream details at : https://rhn.redhat.com/errata/RHBA-2014-0295.html

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

i386:
6213fb856d9676fab217427e01505d1b54d0826da5d224b4a51f98f761c1360b tzdata-2014a-1.el6.noarch.rpm
2a9e76ba42d6e8b2ef358393e62d4df330bc548720052404ca8fd225a6d35b58 tzdata-java-2014a-1.el6.noarch.rpm

x86_64:
6213fb856d9676fab217427e01505d1b54d0826da5d224b4a51f98f761c1360b tzdata-2014a-1.el6.noarch.rpm
2a9e76ba42d6e8b2ef358393e62d4df330bc548720052404ca8fd225a6d35b58 tzdata-java-2014a-1.el6.noarch.rpm

Source:
a09273c4e1130f587024985c3cd7f34d69a803dd70e4f2159baf69d19c6d408a tzdata-2014a-1.el6.src.rpm