There is an out-of-bounds write in checkType located in etc.c in w3m 0.5.3. It can be triggered by sending a crafted HTML file to the w3m binary. It allows an attacker to cause Denial of Service or possibly have unspecified other impact.
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
Vulmon