# Claude Mythos 5.2

> Claude Fable 5.2 without certain cyber and biology safeguards — for verified organizations only, released November 2026.

- Maker: Anthropic
- Line: Claude Fable / Mythos (Mythos-class)
- Canonical page: https://ai-tldr.dev/models/claude-mythos-5-2/
- Updated: 2026-11-09

## In short

Claude Mythos 5.2 is the restricted-access half of Anthropic's 9 November 2026 Mythos-class release. It has a 1M-token context window and costs $8.00 per million input tokens and $40.00 per million output tokens. You can use it through Claude API.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 1M (max output 128K) | [1] |
| Input price | $8.00 / 1M tokens (cached $0.20) | [2] |
| Output price | $40.00 / 1M tokens | [2] |
| Licence | Proprietary · API only | [1] |
| Released | 9 November 2026 | [3] |
| Parameters | Undisclosed | [1] |
| Knowledge cutoff | June 2026 | [1] |

## Sources

1. [Anthropic pricing](https://platform.claude.com/docs/en/about-claude/pricing)
2. [Claude Mythos 5.2 model page](https://platform.claude.com/docs/en/models/mythos-5-2/overview)
3. [Introducing Claude Fable 5.2 and Claude Mythos 5.2](https://www.anthropic.com/claude-fable-and-mythos-5-2)

## Overview

Claude Mythos 5.2 is the restricted-access half of Anthropic's 9 November 2026 Mythos-class release. It is the same underlying model as Claude Fable 5.2 without certain cybersecurity and biology safeguards, and Anthropic offers it only to organizations verified through its verification programs: cybersecurity professionals apply through the Cyber Verification Program and life-sciences researchers through the Life Sciences Verification Program. Claude Enterprise customers can also use it inside Claude Security without joining the Cyber Verification Program.

It shares Claude Fable 5.2's specifications and pricing: a 1M-token context window, up to 128K output tokens, text and image input, adaptive thinking that is always on with a default effort of high, and a June 2026 reliable knowledge cutoff. Standard pricing is $8 per million input tokens and $40 per million output tokens, with cache reads at $0.20 per million. The API model ID is claude-mythos-5-2, and it is offered on the Claude API, Amazon Bedrock, Claude Models on Google Cloud and Microsoft Foundry. Anthropic says output is up to 30% faster than Claude Fable 5.1 and Claude Mythos 5.1.

Anthropic reports Claude Mythos 5.2 at 89.6% on CVE Rediscovery against 78.3% for Mythos 5.1, at 76.3% on CyScenarioBench against 61.7% for Mythos 5.1, and at 85.1% on 24-hour de novo binder design against 79.1% for Mythos 5.1. In one tester's audit it found 10.2% more vulnerabilities than Claude Opus 5.5 and 14.4% more than Claude Mythos 5.1, and Anthropic reports that it accurately modeled 28 of the 34 virus capsid structures it attempted.

## Benchmarks

- CVE Rediscovery (cybersecurity): 89.6% ([source](https://www.anthropic.com/claude-fable-and-mythos-5-2))
- De novo binder design, 24 hr (protein design): 85.1% ([source](https://www.anthropic.com/claude-fable-and-mythos-5-2))
- CyScenarioBench (cybersecurity): 76.3% ([source](https://www.anthropic.com/claude-fable-and-mythos-5-2))
- Terminal-Bench-Science 0.1: 75.3% ([source](https://www.anthropic.com/claude-fable-and-mythos-5-2))

## Pricing

- Input: $8.00 / 1M tokens
- Cached input: $0.20 / 1M tokens
- Output: $40.00 / 1M tokens

Same specifications and pricing as Claude Fable 5.2; Batch API 50% off.

Source: https://platform.claude.com/docs/en/models/mythos-5-2/overview

## Strengths

- Same model as Claude Fable 5.2 with safeguards loosened for verified cybersecurity and life-sciences work
- 89.6% on CVE Rediscovery, up from 78.3% for Claude Mythos 5.1
- 76.3% on CyScenarioBench, up from 61.7% for Claude Mythos 5.1
- 85.1% on 24-hour de novo binder design, up from 79.1% for Claude Mythos 5.1
- 1M-token context window and 128K max output at Claude Fable 5.2's $8/$40 per MTok pricing

## Best for

- Find and rediscover software vulnerabilities for defensive security work inside a verified organization.
- Support life-sciences research such as protein binder design and capsid structure prediction where general-availability safeguards would block the work.
- Use it in Claude Security on Claude Enterprise for vulnerability scanning without a separate Cyber Verification Program enrollment.
- Move from Claude Mythos 5.1 at a lower per-token price once your verification programme grants access.

## How to access

- [Claude API](https://platform.claude.com/docs/en/models/mythos-5-2/overview) — model id `claude-mythos-5-2`

## Claude Fable / Mythos (Mythos-class) versions

- [Claude Fable 5.2](https://ai-tldr.dev/models/claude-fable-5-2/) (9 November 2026)
- Claude Mythos 5.2 (9 November 2026) — this page
- [Claude Fable 5.1](https://ai-tldr.dev/models/claude-fable-5-1/) (1 September 2026)
- [Claude Mythos 5.1](https://ai-tldr.dev/models/claude-mythos-5-1/) (1 September 2026)
- [Claude Fable 5](https://ai-tldr.dev/models/claude-fable-5/) (9 June 2026)
- [Claude Mythos 5](https://ai-tldr.dev/models/claude-mythos-5/) (9 June 2026)
- [Claude Mythos Preview](https://ai-tldr.dev/models/claude-mythos-preview/) (April 2026)

## FAQ

### How do I get access to Claude Mythos 5.2?

Claude Mythos 5.2 is available only to organizations verified through Anthropic's verification programs. Cybersecurity professionals apply through the Cyber Verification Program and life-sciences researchers through the Life Sciences Verification Program. Claude Enterprise customers can also use it inside Claude Security. Claude Fable 5.2 is the generally available version of the same model.

### How is Claude Mythos 5.2 different from Claude Fable 5.2?

They are the same underlying model. Claude Mythos 5.2 ships without certain cybersecurity and biology safeguards, while Claude Fable 5.2's safeguards block most cybersecurity-related tasks and most research biology tasks. The two share specifications and pricing.

### How much does Claude Mythos 5.2 cost?

Claude Mythos 5.2 costs $8 per million input tokens and $40 per million output tokens, with cache reads at $0.20 per million and 50% off through the Batch API. Fast mode, at $16 and $80 per million tokens, is open only to organizations in Anthropic's verification programs.

### How does Claude Mythos 5.2 compare with Claude Mythos 5.1?

Anthropic reports Claude Mythos 5.2 at 89.6% on CVE Rediscovery against 78.3% for Mythos 5.1, 76.3% on CyScenarioBench against 61.7%, and 85.1% on 24-hour de novo binder design against 79.1%. It is priced at $8/$40 per MTok, and Anthropic says its output is up to 30% faster than Mythos 5.1.

## Links

- [Introducing Claude Fable 5.2 and Claude Mythos 5.2](https://www.anthropic.com/claude-fable-and-mythos-5-2)
- [Claude Mythos 5.2 model page](https://platform.claude.com/docs/en/models/mythos-5-2/overview)
- [Claude Fable 5.2 and Mythos 5.2 system card](https://www.anthropic.com/document/claude-fable-5-2-mythos-5-2-system-card)
- [Anthropic pricing](https://platform.claude.com/docs/en/about-claude/pricing)

Source: AI/TLDR LLM registry, https://ai-tldr.dev/models/claude-mythos-5-2/