Updated firefox and thunderbird packages fix security vulnerabilities:
Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause Firefox or Thunderbird to crash or, potentially, execute arbitrary code with the privileges of the user running it (CVE-2015-0836, CVE-2015-0831, CVE-2015-0827).
An information leak flaw was found in the way Firefox and Thunderbird implemented autocomplete forms. An attacker able to trick a user into specifying a local file in the form could use this flaw to access the contents of that file (CVE-2015-0822).