Security issues were identified and fixed in mozilla-thunderbird:

Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbird
before 3.0.11 and 3.1.x before 3.1.7, and SeaMonkey before 2.0.11 do
not properly validate downloadable fonts before use within an operating
system's font implementation, which allows remote attackers to execute
arbitrary code via vectors related to @font-face Cascading Style Sheets
(CSS) rules (CVE-2010-3768).

The line-breaking implementation in Mozilla Firefox before 3.5.16 and
3.6.x before 3.6.13, Thunderbird before 3.0.11 and 3.1.x before 3.1.7,
and SeaMonkey before 2.0.11 on Windows does not properly handle long
strings, which allows remote attackers to execute arbitrary code
via a crafted document.write call that triggers a buffer over-read
(CVE-2010-3769).

Multiple unspecified vulnerabilities in the browser engine in Mozilla
Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbird before
3.0.11 and 3.1.x before 3.1.7, and SeaMonkey before 2.0.11 allow
remote attackers to cause a denial of service (memory corruption and
application crash) or possibly execute arbitrary code via unknown
vectors (CVE-2010-3776).

Unspecified vulnerability in Mozilla Firefox 3.6.x before 3.6.13
and Thunderbird 3.1.x before 3.1.7 allows remote attackers to cause
a denial of service (memory corruption and application crash) or
possibly execute arbitrary code via unknown vectors (CVE-2010-3777).

Unspecified vulnerability in Mozilla Firefox 3.5.x before 3.5.16,
Thunderbird before 3.0.11, and SeaMonkey before 2.0.11 allows
remote attackers to cause a denial of service (memory corruption and
application crash) or possibly execute arbitrary code via unknown
vectors (CVE-2010-3778).

Packages for 2009.0 are provided as of the Extended Maintenance
Program. Please visit this link to learn more:
http://store.mandriva.com/product_info.php?cPath=149&products_id=490

Additionally, some packages which require so, have been rebuilt and
are being provided as updates.