w3m before 0.3.2.2 does not properly escape HTML tags in the ALT attribute of an IMG tag, which could allow remote attackers to access files or cookies.
http://www.securityfocus.com/bid/6794
http://www.redhat.com/support/errata/RHSA-2003-045.html
http://www.redhat.com/support/errata/RHSA-2003-044.html
http://www.iss.net/security_center/static/11266.php
http://www.debian.org/security/2003/dsa-251
http://www.debian.org/security/2003/dsa-250
http://www.debian.org/security/2003/dsa-249
http://sourceforge.net/project/shownotes.php?release_id=126233