Here are the details from the Slackware 13.1 ChangeLog:
+--------------------------+
patches/packages/xrdb-1.0.9-i486-1_slack13.1.txz: Upgraded.
This fixes a security issue where improperly sanitized input could lead to
privilege escalation or arbitrary command execution as root.
For more information, see:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-0465
(* Security fix *)
+--------------------------+


Where to find the new packages:
+-----------------------------+

HINT: Getting slow download speeds from ftp.slackware.com?
Give slackware.osuosl.org a try. This is another primary FTP site
for Slackware that can be considerably faster than downloading
directly from ftp.slackware.com.

Thanks to the friendly folks at the OSU Open Source Lab
(http://osuosl.org) for donating additional FTP and rsync hosting
to the Slackware project! :-)

Also see the "Get Slack" section on http://slackware.com for
additional mirror sites near you.

Updated package for Slackware 12.0:
ftp://ftp.slackware.com/pub/slackware/slackware-12.0/patches/packages/xrdb-1.0.9-i486-1_slack12.0.tgz

Updated package for Slackware 12.1:
ftp://ftp.slackware.com/pub/slackware/slackware-12.1/patches/packages/xrdb-1.0.9-i486-1_slack12.1.tgz

Updated package for Slackware 12.2:
ftp://ftp.slackware.com/pub/slackware/slackware-12.2/patches/packages/xrdb-1.0.9-i486-1_slack12.2.tgz

Updated package for Slackware 13.0:
ftp://ftp.slackware.com/pub/slackware/slackware-13.0/patches/packages/xrdb-1.0.9-i486-1_slack13.0.txz

Updated package for Slackware x86_64 13.0:
ftp://ftp.slackware.com/pub/slackware/slackware64-13.0/patches/packages/xrdb-1.0.9-x86_64-1_slack13.0.txz

Updated package for Slackware 13.1:
ftp://ftp.slackware.com/pub/slackware/slackware-13.1/patches/packages/xrdb-1.0.9-i486-1_slack13.1.txz

Updated package for Slackware x86_64 13.1:
ftp://ftp.slackware.com/pub/slackware/slackware64-13.1/patches/packages/xrdb-1.0.9-x86_64-1_slack13.1.txz

Updated package for Slackware -current:
ftp://ftp.slackware.com/pub/slackware/slackware-current/slackware/x/xrdb-1.0.9-i486-1.txz

Updated package for Slackware x86_64 -current:
ftp://ftp.slackware.com/pub/slackware/slackware64-current/slackware64/x/xrdb-1.0.9-x86_64-1.txz


MD5 signatures:
+-------------+

Slackware 12.0 package:
32527c76943707b282a3f4b084e1f4d6 xrdb-1.0.9-i486-1_slack12.0.tgz

Slackware 12.1 package:
a1ac49f09f1b14caee33d508aaced37c xrdb-1.0.9-i486-1_slack12.1.tgz

Slackware 12.2 package:
7b102c0a2a6173f945fa95ad9098a86f xrdb-1.0.9-i486-1_slack12.2.tgz

Slackware 13.0 package:
1ea7bd9486efaccdf520d71997c42681 xrdb-1.0.9-i486-1_slack13.0.txz

Slackware x86_64 13.0 package:
8a070b5dea8b98cf4defb9cb7a14f019 xrdb-1.0.9-x86_64-1_slack13.0.txz

Slackware 13.1 package:
f86dd76e5e164c3e5e471063597fe50e xrdb-1.0.9-i486-1_slack13.1.txz

Slackware x86_64 13.1 package:
a1f5e38934e69dd20ecb93ccc3e45331 xrdb-1.0.9-x86_64-1_slack13.1.txz

Slackware -current package:
82f546e63687aeaa6e6921bdfddbe403 x/xrdb-1.0.9-i486-1.txz

Slackware x86_64 -current package:
f2e9fec7c1cc69ae0ae76db68ae4b930 x/xrdb-1.0.9-x86_64-1.txz


Installation instructions:
+------------------------+

Upgrade the package as root:
# upgradepkg xrdb-1.0.9-i486-1_slack13.1.txz


+-----+

Slackware Linux Security Team
http://slackware.com/gpg-key