The w3m program is a pager (or text file viewer) that can also be used as a text mode web browser.
It was discovered that w3m is affected by the previously published "null prefix attack", caused by incorrect handling of NULL characters in X.509 certificates. If an attacker is able to get a carefully-crafted certificate signed by a trusted Certificate Authority, the attacker could use the certificate during a man-in-the-middle attack and potentially confuse w3m into accepting it by mistake. (CVE-2010-2074)
All w3m users should upgrade to these updated packages, which contain a backported patch to correct this issue.