Anonymous poster found a way to spam a bitcoin node and make it use more than the advertised "minimum requirements" , up to 4GB of memory for Bitcoin. This causes low end devices (eg. < 4 GB raspberry pis) to shut down the process due to memory exhaustion.

The issue was originally found on BSV by the same poster, where due to their code changes, it can push the memory usage up to 256GB of ram, virtually crashing any (of the few) BSV nodes in the network.

The OP has yet to share more details, presumably aiming for a bug bounty, possibly from BSV. This leaves uncertainty about whether it's truly a bug in Bitcoin Core.

Allowing some spam is inevitable in these system, to avoid hurting good traffic, and having 4GB of memory usage under this 'attack' doesn't seem like a big deal.

However this is a big issue for BSV, since every node can be taken down from a single attacker apparently.