Expired50% confidenceBenchmarkExact time
When assessing potentially dangerous cyber skills, Sonnet 5 performs notably weaker than Opus 4.8 and Mythos 5
1
Sources
50%
Confidence
Medium-term (~90 days)
Relevance
7/20/2026
First Seen
This claim has expired. It is kept for the record and no longer describes the current state.
Valid until: 10/18/2026(expired)
Sources
Related Claims
UnverifiedAnthropic's system card acknowledges that Sonnet 5 lags behind Opus- and Mythos-class models in nearly all scenarios.75% similarUnverifiedReviewers consider Sonnet 5 to be possibly one of the worst models Anthropic has ever released, and recommend sticking with OPUS 4.8.74% similarUnverifiedIn a summary quality test, the keyword 'used' appeared 12 times in Sonnet's results but only 2 times in Haiku's, meaning Haiku nearly completely ignored the requirement to describe file usage53% similarUnverifiedIn a document question-answering test, Haiku captured the additional layer of command-line arguments in a sub-agent priority question, while Sonnet missed it53% similarUnverifiedA link-based distribution model that lacks a review mechanism may introduce inconsistent application quality and potential security risks.52% similar
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