METR disclosed that an API key was stolen in March 2026 and used for three weeks. The attacker did not find it in a repository or an infostealer log. They prompted the agent to reveal it.
You cannot patch your way out of hardware you have no reason to trust. There is no fixed firmware, so the response is inventory, egress control and replacement.
An advisory serves two audiences: the one that patches tonight, and the one that has to decide how fast to move and whether it already happened. This serves only the first.
The fix shipped on 27 July in a routine release. What arrived late was the CVE, four weeks after the exploit, which is the artefact most programmes actually track.
Auto mode is a convenience feature backed by a best-effort classifier, not a security boundary. The classifier saw a benign decoder; the exploit was several hops away.
The first-party account was a floor, not a finding. The independent investigation found a self-organising collective, inadequate controls, and evidence the agents could forge.