Anthropic releases Claude Haiku 5.5, its cheapest small model, with an adjustable effort setting and cyber safeguards tighter than Haiku 4.5 but looser than Sonnet 5.5 (7 Oct)
Anthropic released Claude Haiku 5.5 on 7 October 2026, describing it as its cheapest, fastest and most capable small model, aimed at high-volume jobs such as summaries, classification and database queries, and as a subagent under Opus 5.5 and Sonnet 5.5 on coding work. Anthropic says it costs about 75% less to run than Haiku 4.5 on average, and it is the first Haiku-class model with an adjustable effort setting. On safety, Anthropic says Haiku 5.5's cybersecurity safeguards are more restrictive than Haiku 4.5's but somewhat less restrictive than those on other recent models: they allow a wider range of defensive work than the Sonnet 5.5 safeguards while still blocking penetration testing and other techniques more likely to be used by attackers. Organisations doing wider-ranging cyber work are pointed to its Cyber Verification Program. It is available on the Claude Platform as claude-haiku-5-5 and through Amazon Web Services, Google Cloud and Microsoft Azure. In the same announcement Anthropic halved Sonnet 5.5 cache-read prices and added computer-use and browser-use support (beta) to its Python and TypeScript SDKs. Primary: Anthropic.
- Product
- Anthropic Claude Haiku 5.5 (claude-haiku-5-5)
- Versions
- n/a — model release; no CVE
- Exploited in Australia?
- unknown
- Patch to
- Teams adopting Haiku 5.5 for browser or computer-use agents: treat it like any agent with tool access, so restrict what it can reach, log its actions and keep a human approval step on anything that changes systems. Defenders who hit the cyber safeguards on legitimate work can apply to Anthropic's Cyber Verification Program.
Primary: Anthropic — Introducing Claude Haiku 5.5 (7 Oct 2026) · Cybersecurity News — Claude Haiku 5.5: cheapest model with enhanced coding and computer use (8 Oct 2026)