Anthropic Releases Claude Sonnet 5.5, Bringing Advanced Cyber Safeguards to Lower-Cost Models

Anthropic has released Claude Sonnet 5.5, a faster and more affordable model designed for everyday business work that delivers cyber skills comparable to its higher-priced counterpart, Claude Opus 5.
Because the model's cyber capabilities represent a large improvement over previous iterations—now rivaling top-tier systems—Anthropic has shipped Sonnet 5.5 with flagship cyber protections previously reserved for its most advanced models. While routine tasks like spreadsheet formatting and polished document creation remain open, higher-risk requests such as penetration testing and exploit generation are automatically routed or restricted.
The rollout reflects a broader trend of advanced cyber skills trickling down to cheaper models on a timeline measured in weeks rather than years. To balance accessibility and security, Anthropic requires API developers to opt in to automatic fallback routing, while verified defenders can apply for tiered access through an expanded Cyber Verification Program.