Mythos Preview

Reported Context (3)

In the vulnerability ecosystem, the release of Anthropic’s Claude Mythos Preview reinforced the growing relevance of frontier models to offensive and defensive security research. Recorded Future Reports 215 Actively Exploited CVEs and Expanding Supply-Chain Threats in H1 2026
Fable (technically known as Claude Fable 5) was presented as the user-safe version of Mythos Preview, a limited-release frontier model with advanced cybersecurity capabilities, including red teaming, vulnerability Anthropic’s Fable Export Controls Highlight Risks of Frontier AI Dependence
review, and internal controls. Anthropic refers to Project Glasswing as an early signal, stating that Mythos Preview found more than ten thousand high- and critical-severity software vulnerabilities across important Governments Advance Cybersecurity, Privacy and AI Rules in New Policy Developments

CVE (5)

Malware (50)

People (4)

Threat Actors (14)

MITRE ATT&CK (13)

Vendors (27)

Products (65)

Tools (13)

Industries (26)

Countries (12)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.