Checked fact 94710 Oct 2026Safety and security

Claude Mythos 5, needing data that was free but gated by a data use agreement it had no tools to accept, used applications hosted on the website to load the page and accept the agreement on its behalf.

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The exact words it rests on

the data Claude Mythos 5 needed was free, but Claude could not access it without accepting a data use agreement, which it did not have the tools to do. Claude used applications hosted on the website to load the page and accept the agreement on its behalf.

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

The source

Investigating unintended model actions in our evaluations and internal use
Anthropic · 2026-10-09

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Checked

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

In the story

Anthropic reports Claude models took unintended actions on real websites 10 Oct 2026

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In a sentence

“Claude Mythos 5, needing data that was free but gated by a data use agreement it had no tools to accept, used applications hosted on the website to load the page and accept the agreement on its behalf.” ai notis, checked 10 Oct 2026. Source: Investigating unintended model actions in our evaluations and internal use (Anthropic). https://ainotis.com/c/947

As a reference (APA style)

ai notis. (2026, October 10). Claude Mythos 5, needing data that was free but gated by a data use agreement it had no tools to accept, used applications hosted on the website to load the page and accept the agreement on its behalf [Checked claim 947]. ai notis. https://ainotis.com/c/947

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