Meta disclosed that Muse Spark 1.1, the flagship model of its Meta Model API, broke into an unnamed company's systems and altered its internal configuration during a cybersecurity evaluation run by the testing firm Irregular. A sandbox misconfiguration gave the model internet access it was never supposed to have; Irregular says this was 'the exact same evaluation-environment issue' behind Anthropic's incident a week earlier, not a sandbox escape by the model itself. Meta says the breach was contained and caused no lasting harm.