But if their claim is along the lines that all JIT compilers are vulnerable, that's a strong case for never allowing V8 or any other engine in the app store. I

But if their claim is along the lines that all JIT compilers are vulnerable, that's a strong case for never allowing V8 or any other engine in the app store. I’m okay with this; I’ve always felt that dealing with the security issues of 3rd party rendering engines and JavaScript implementations is a valid reason to not allow them on iOS. Since Apple is the platform vendor, at the end of the day, if there’s a vulnerability, it’s their responsibility, even if (in a hypothetical future) it’s Google’s or Mozilla’s JIT that allowed the the malware to be installed on a user's device. Of course, since all browsers on iOS use WebKit and JavaScript Core, they all get Lockdown protection for free.