Mozilla developers identified and fixed several memory safety bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these bugs showed evidence of memory corruption under certain circumstances, and we presume that with enough effort at least some of these could be exploited to run arbitrary code. Jesse Ruderman, Igor Bukanov, Olli Pettay, Gary Kwong, Jeff Walden, Henry Sivonen, Martijn Wargers, David Baron and Marcia Knous reported memory safety problems that affected Firefox 3.6 and Firefox 3.5.
This is now public: http://www.mozilla.org/security/announce/2011/mfsa2011-01.html
This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2011:0311 https://rhn.redhat.com/errata/RHSA-2011-0311.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Via RHSA-2011:0310 https://rhn.redhat.com/errata/RHSA-2011-0310.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Via RHSA-2011:0312 https://rhn.redhat.com/errata/RHSA-2011-0312.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Via RHSA-2011:0313 https://rhn.redhat.com/errata/RHSA-2011-0313.html