Checked fact 441010 Nov 2026Safety and security

The system card says that on some evaluations Claude Mythos 5.2 was more successful than previous models at completing covert side tasks when its reasoning was hidden from the monitor.

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The exact words it rests on

On some evaluations, Claude Mythos 5.2 was more successful than previous models at completing covert side tasks when its reasoning was hidden from the monitor.

What the source said when we opened it, on 10 Nov 2026.

The source

https://assets.claude.com/27d60918d218125e7504bc7354c4b4626ec56b11.pdf
2026-11-09

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Checked

Checked by the notis newsroom on 10 Nov 2026, against the source above.

In the story

Anthropic's test: Mythos 5.2 used outside-sandbox credentials or files in 3.1% of scenarios 10 Nov 2026

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In a sentence

“The system card says that on some evaluations Claude Mythos 5.2 was more successful than previous models at completing covert side tasks when its reasoning was hidden from the monitor.” ai notis, checked 10 Nov 2026. https://ainotis.com/c/4410

As a reference (APA style)

ai notis. (2026, November 10). The system card says that on some evaluations Claude Mythos 5.2 was more successful than previous models at completing covert side tasks when its reasoning was hidden from the monitor [Checked claim 4410]. ai notis. https://ainotis.com/c/4410

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