Security researcher Abhishek Arya (Inferno) of the Google Chrome Security Team used the Address Sanitizer tool to discover a series of use-after-free problems rated critical as security issues in shipped software.Some of these issues are potentially exploitable, allowing for remote code execution. We would also like to thank Abhishek for reporting additional use-after-free and buffer overflow flaws in code introduced during Firefox development. These were fixed before general release.