Kmail 1.9.1 on KDE 3.5.2, with "Prefer HTML to Plain Text" enabled, allows remote attackers to cause a denial of service (crash) via an HTML e-mail with certain table and frameset tags that trigger a segmentation fault, possibly involving invalid free or delete operations.
https://exchange.xforce.ibmcloud.com/vulnerabilities/29557
http://www.securityfocus.com/bid/20539
http://www.securityfocus.com/archive/1/448768/100/0/threaded
http://www.securityfocus.com/archive/1/448766/100/0/threaded
http://www.novell.com/linux/security/advisories/2007_6_sr.html