Upgrade to Firefox 3.6.2 ,coze mozilla has fixed a critical security issue.

“Security researcher Evgeny Legerov of Intevydis reported that the WOFF decoder contains an integer overflow in a font decompression routine. This flaw could result in too small a memory buffer being allocated to store a downloadable font. An attacker could use this vulnerability to crash a victim’s browser and execute arbitrary code on his/her system.”