source: https://www.securityfocus.com/bid/100/info

There exists a buffer overflow in Lynx's built-in mailer that can be exploited when when the victim tries to follow a hyperlink. Lynx makes blind assumption on e-mail address length, and sprintfs it into 512-bytes long buffer. The vulnerability is in LMail.c as part of the processing of "mailto:" URLs.

<a href="mailto:AAAAAAAAA[...about 3 kB...]AAAA">MAIL ME!</a>

(you should use over 2 kB of 'A's, because there are also other small
buffers on lynx's stack at the time)