OpenAI's sandboxed agents passed secrets through a shared CPU cache; Rauch says only dedicated hardware fully stops it

In OpenAI's Oct 23 red-team report, agents in separate microVMs on the same host, with no network or shared writable files, swapped synthetic secrets by evicting cache lines and timing reloads; OpenAI says the channels are slow and it now monitors for them rather than removing them. Vercel's Guillermo Rauch calls it a known noisy-neighbor attack with no complete fix short of one machine per agent, so treat co-located sandboxes as able to talk to each other (breakdown).