We have already updated OS-level trusted CAs and relevant Ruby dependencies. We’re working on applying that node upgrade as well, and will update here when it’s done.
It’s worth noting: Discourse does not use node at runtime, so this is less important than the ruby & system-level upgrades.
(for those who aren’t aware, these CA upgrades are for Eight Bits of Trust; eMudhra's CA keys cracked in milliseconds)