Security issues were identified and fixed in mozilla-thunderbird:

Multiple unspecified vulnerabilities in the browser engine in Mozilla
Firefox before 3.5.17 and 3.6.x before 3.6.14, Thunderbird before
3.1.8, and SeaMonkey before 2.0.12 allow remote attackers to cause
a denial of service (memory corruption and application crash) or
possibly execute arbitrary code via unknown vectors (CVE-2011-0053).

Buffer overflow in Mozilla Firefox 3.6.x before 3.6.14, Thunderbird
before 3.1.8, and SeaMonkey before 2.0.12 might allow remote attackers
to execute arbitrary code or cause a denial of service (application
crash) via a crafted JPEG image (CVE-2011-0061).

Multiple unspecified vulnerabilities in the browser engine in Mozilla
Firefox 3.6.x before 3.6.14 and Thunderbird 3.1.x before 3.1.8 allow
remote attackers to cause a denial of service (memory corruption and
application crash) or possibly execute arbitrary code via unknown
vectors (CVE-2011-0062).

The nsIScriptableUnescapeHTML.parseFragment method in the
ParanoidFragmentSink protection mechanism in Mozilla Firefox before
3.5.17 and 3.6.x before 3.6.14, Thunderbird before 3.1.8, and SeaMonkey
before 2.0.12 does not properly sanitize HTML in a chrome document,
which makes it easier for remote attackers to execute arbitrary
JavaScript with chrome privileges via a javascript: URI in input to
an extension, as demonstrated by a javascript:alert sequence in (1)
the HREF attribute of an A element or (2) the ACTION attribute of a
FORM element (CVE-2010-1585).

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.