@alwayscurious @swordgeek @theearthisapringle That happens a lot more in Chrome than Firefox probably because of their SV cowboy attitudes about performance, but it might also be a matter of more eyes/valuable targets.
In any case, if you have a real kill switch for JIT, or even better an option to disable the native zomg-UB-is-so-fast engine and use DukTape or something (I suspect you could even do that with an extension running DukTape compiled to wasm...), even these can be mitigated without updates.