Anthropic Resolves Elevated Errors Across Five Claude Models

Anthropic marked an October 25, 2026 incident involving elevated errors across five Claude models resolved at 07:53 UTC. The incident affected four services, and the company said it had deployed a fix and monitored recovery.

• The incident began at 23:05 PT on October 24, equivalent to 06:05 UTC on October 25, and was marked resolved at 07:53 UTC.· 1 source
• The five affected models named in the incident record were Claude Mythos 5.1, Fable 5.1, Opus 5.5, Sonnet 5.5 and Haiku 5.5.· 1 source
• The incident affected claude.ai, the Claude API, Claude Code and Claude Cowork; Anthropic reported deploying a fix at 06:35 UTC and monitoring recovery.· 1 source