Quoting Boris Cherny

Boris Cherny, an Anthropic employee, stated that Claude Opus 5 is the company's least prompt-injectable model yet, based on prompt injection evaluations and red teaming results detailed in the system card on page 73.

More than any of these eval scores, what is most exciting to me is something else: Opus 5 is our least prompt injectable model yet. It is a bit buried in the system card, but across PI evals and red teaming, Opus 5 is very hard to prompt inject successfully. — Boris Cherny https://twitter.com/bcherny/status/2080713091688583312 , here's that System Card section https://www-cdn.anthropic.com/c5fbac3f0b1280a933ebd26d3cb8bb9f5bdeaf48/Claude%20Opus%205%20System%20Card.pdf page=73 , page 73 Tags: prompt-injection https://simonwillison.net/tags/prompt-injection , anthropic https://simonwillison.net/tags/anthropic , claude https://simonwillison.net/tags/claude , generative-ai https://simonwillison.net/tags/generative-ai , ai https://simonwillison.net/tags/ai , llms https://simonwillison.net/tags/llms , boris-cherny https://simonwillison.net/tags/boris-cherny