The remote host is missing an update to fml announced via advisory DSA 088-1.
The fml (a mailing list package) as distributed in Debian GNU/Linux 2.2 suffers from a cross-site scripting problem. When generating index pages for list archives the `<' and `>' characters were not properly escaped for subjects. This has been fixed in version 3.0+beta.20000106-5, and we recommend that you upgrade your fml package to that version. Upgrading will automatically regenerate the index pages.