Lynx, lynx-ssl, and lynx-cur before 2.8.6dev.8 allow remote attackers to cause a denial of service (infinite loop) via a web page or HTML email that contains invalid HTML including (1) a TEXTAREA tag with a large COLS value and (2) a large tag name in an element that is not terminated, as demonstrated by mangleme. NOTE: a followup suggests that the relevant trigger for this issue is the large COLS value.
Lynx 2.8.5, and other versions before 2.8.6dev.15, allows remote attackers to execute arbitrary commands via (1) lynxcgi:, (2) lynxexec, and (3) lynxprog links, which are not properly restricted in the default configuration in some environments.