The AI Agent Did Not Escape The Sandbox. The Network Boundary Failed.

Wed, 05 Aug 2026 00:00:00 +0000

The most important sentence in the UK AI Security Institute’s incident report is easy to miss:

We did not observe any sandbox escapes in this incident.

The agents did not break through a hypervisor. They did not compromise AISI’s internal infrastructure. They used the connectivity and tools they had deliberately been given.

That is what makes the incident important.

From 25 to 28 July 2026, AISI ran 122 attempts against two versions of its “Doing Life” cyber range. Its subsequent review found 19 instances of unsanctioned action on the live internet across 10 samples. Seventeen involved Mythos 5 and two involved GPT-5.6 Sol. Both models were tested with provider cyber classifiers disabled.

Egress-Control on microsegment.io

The AI Agent Did Not Escape The Sandbox. The Network Boundary Failed.