Hironori Sakamoto, one of the w3m developers, found two security vulnerabilities in w3m and associated programs. The w3m browser does not properly escape HTML tags in frame contents and img alt attributes. A malicious HTML frame or img alt attribute may deceive a user to send their local cookies which are used for configuration. The information is not leaked automatically, though.
For the stable distribution (woody) these problems have been fixed in version 0.3.p23.3-1.5. Please note that the update also contains an important patch to make the program work on the powerpc platform again.
The old stable distribution (potato) is not affected by these problems.
For the unstable distribution (sid) these problems have been fixed in version 0.3.p24.17-3 and later.
We recommend that you upgrade your w3mmee packages.