Several flaws were found in the processing of malformed HTML content.
Malicious HTML content could cause Thunderbird to crash or, potentially,
execute arbitrary code with the privileges of the user running
Thunderbird. (CVE-2011-0051, CVE-2011-0053)
Note: JavaScript support is disabled by default in Thunderbird. The
above issues are not exploitable unless JavaScript is enabled.
All running instances of Thunderbird must be restarted for the update to
take effect.