Anthropic Claude logo

Anthropic Claude Update Version Claude Fable 5 / Claude Mythos 5

Views
46

Your rating
Rate update installation process

Log in to rate this update.
Login

Risk factor
A total of 1 users have rated this update.

Smooth installs 100%
Minor issues 0%
Major issues 0%

Update Summary

Claude Fable 5 and Claude Mythos 5 launched on 2026-06-09. The release adds major capabilities in software engineering, vision, memory, and scientific research, alongside new safety classifiers, fallback behavior to Claude Opus 4.8, and updated data retention rules.

Update Details

Security

  • New safety classifiers block or reroute requests involving cybersecurity, biology and chemistry, and distillation to reduce misuse risk.
  • Fallback to Claude Opus 4.8 is used for potentially risky queries instead of letting Fable 5 respond directly.
  • Expanded safeguards are designed to resist jailbreaks and prevent uplift for offensive cyber tasks and other dual-use misuse.
  • Business customer traffic on Mythos-class models now requires 30-day retention with added privacy protections and access logging.

New Features

  • Claude Fable 5 is now generally available as a Mythos-class model with state-of-the-art performance across coding, knowledge work, vision, and research tasks.
  • Claude Mythos 5 is available to trusted users with some safeguards lifted for cybersecurity and later biology use cases.
  • New trusted access programs are planned for cybersecurity organizations and biology researchers.
  • Developers can use claude-fable-5 via the Claude API.

Known Issues

  • Safeguards are intentionally conservative and may flag some harmless requests as false positives.
  • Fable 5 is not fully included on subscription plans after 2026-06-22 unless usage credits are used, subject to capacity.

Hints

  • Claude Fable 5 is available everywhere today, while Claude Mythos 5 is restricted to Glasswing partners and select biology researchers.
  • Pricing is $10 per million input tokens and $50 per million output tokens.
  • On Pro, Max, Team, and seat-based Enterprise plans, Fable 5 is included at no extra cost from 2026-06-09 through 2026-06-22, then requires usage credits.
  • On the Claude API and consumption-based Enterprise plans, Fable 5 is fully available from launch.
Product Information

Vendor: Anthropic

Product: Claude

Product type: Other

Application category: Business

Platform: Web

Version: Claude Fable 5 / Claude Mythos 5

Vendor release date: Jun 9, 2026

Published on updatealert.io: Jun 10, 2026

Description: AI assistant for drafting, analysis, coding, and enterprise workflows.

View All Updates