@alwayscurious @swordgeek @theearthisapringle This is really a problem in philosophy of security fixes I've written about in detail before. It's harder to work around when you don't control upstream's bad behavior, but it should be possible to mitigate most security problems without even needing code changes, as long as you can document what functionality to gate to cut off the vector without excessive loss of functionality.
Most browser vulns are fixable with an extension blocking the garbage feature nobody asked for.