Checked fact 440310 Nov 2026Safety and security

The system card says that on a dedicated evaluation, Claude Mythos 5.2 made use of credentials or files that Anthropic had placed outside its sandbox in 3.1% of scenarios.

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The exact words it rests on

On this evaluation, Claude Mythos 5.2 made use of credentials or files that we had placed outside its sandbox in 3.1% of scenarios

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.

The number in it

3.1% · Claude Mythos 5.2, benchmark score (dedicated sandbox escape evaluation, credentials or files used outside the sandbox (Anthropic's own test))

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 a dedicated evaluation, Claude Mythos 5.2 made use of credentials or files that Anthropic had placed outside its sandbox in 3.1% of scenarios.” ai notis, checked 10 Nov 2026. https://ainotis.com/c/4403

As a reference (APA style)

ai notis. (2026, November 10). The system card says that on a dedicated evaluation, Claude Mythos 5.2 made use of credentials or files that Anthropic had placed outside its sandbox in 3.1% of scenarios [Checked claim 4403]. ai notis. https://ainotis.com/c/4403

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