Overview
- Anthropic logged elevated authentication errors on its status page starting around 09:58 UTC on Friday, November 13, 2026, and the company says engineers are actively investigating.
- The impact varies by component with claude.ai marked as a major outage, Claude Code and Claude Console listed as partial outages, and the Claude API reported as operational.
- Anthropic identified a simultaneous Microsoft 365 service incident as the cause of errors in its Microsoft 365 connector used for mail, calendar, and search integrations.
- User reports from the United States, India, and the United Kingdom describe failed sign‑ins, unexpected logouts, and app‑loading problems while outage monitors showed mixed signals about the scope.
- The episode follows earlier 2026 sign‑in problems and separate session‑token thefts that year, raising continued questions about the platform’s authentication resilience and third‑party dependencies.