Log4j 1.2.13 has problems, fixed in 1.2.14 that prevent its use in JBoss AS 4.2 (part of the EAP product). Log4j is widely used (jgroups, mx4j, velocity, xdoclet, xjavadoc) in RHEL-5 Base, but 1.2.14 is a drop in replacement for 1.2 13 so it shouldn't cause any problems.
Submitting for 3-ack approval.