Yes (from the Google blog post linked elsewhere in the thread):

> CVE-2022-42856, a WebKit remote code execution exploiting a type confusion issue within the JIT compiler (0-day at time of exploitation).

Lockdown mode disables the Webkit JIT.

It's worth mentioning that most of security measures are also possible in the Chromium engine in case you're running that.

I use Bromite (Chromium fork) on my phone which has the option to run with JIT disabled by default, which would've been how Lockdown Mode would stop this exploit. Very rarely do I click the permissions popup to enable it again, mostly for games and demos requiring WASM or depending on heavy Javascript.