LIVE FEED
HIGH OpenAI Rogue Model Compromises Modal and Other Services // FIRST LOOK Microsoft Copilot Super App Merges Chat, Code, and Agents // FIRST LOOK Meta Plans Billions of Personal AI Agents on WhatsApp // FIRST LOOK Meta Launches Enterprise AI Agents and API Services for Business // FIRST LOOK Perplexity Launches Personal Computer AI Agent for Windows PCs // FIRST LOOK Google Gemini API Adds Hooks, Budget Controls, and 3.6 Flash Agents // FIRST LOOK AWS AgentCore Gateway Adds Support for MCP 2026-07-28 Spec // HIGH Modal Sandbox Exposed: Rogue AI Agent Exploits Open Endpoint // HIGH LLMs Break Cryptographic Schemes in New CryptanalysisBench Study // FIRST LOOK Moonshot AI Releases Kimi K3 Open-Weight 2.8T Model Weights //
AI-SECURITY-INSTITUTE

Ai-Security-Institute

2 reports
All LLM Security Agentic AI Industry News Supply Chain Research Prompt Injection First Look: Security Regulatory Adversarial ML Jailbreaks Model Theft Data Poisoning AI Security Tools Security Operations
GPT-5.5 and Claude Mythos Lower Barriers to Offensive AI

GPT-5.5 and Claude Mythos Lower Barriers to Offensive AI

ATLAS OWASP HIGH Significant risk · Prioritise patching ▲ 7.2 Schneier on Security

The UK AI Security Institute has evaluated GPT-5.5 and found it comparable to Claude Mythos in identifying security vulnerabilities, with both models now generally available to the public. This parity raises serious concerns about the lowered barrier to entry for offensive cyber operations, as adversaries can leverage widely accessible models for vulnerability research. Commentary from security experts highlights that LLM-based vulnerability discovery is constrained to known attack patterns, but the existence of jailbreaks means guardrails provide only partial mitigation.

GPT-5.5 Matches Claude Mythos in Vulnerability Discovery

GPT-5.5 Matches Claude Mythos in Vulnerability Discovery

ATLAS OWASP HIGH Significant risk · Prioritise patching ▲ 7.2 Simon Willison

The UK's AI Security Institute has evaluated OpenAI's GPT-5.5 for offensive cybersecurity capabilities, finding it comparable to Anthropic's Claude Mythos model in identifying security vulnerabilities. Unlike Mythos, GPT-5.5 is generally available, meaning its vulnerability-discovery capabilities are accessible to a broad population including malicious actors. This raises significant concerns about the proliferation of AI-assisted exploitation tools at scale.

◉ AI THREAT BRIEFING

Stay ahead of the threat.

Twice-weekly digest of critical AI security developments — every story mapped to MITRE ATLAS and OWASP LLM Top 10. Free.

No spam. Unsubscribe anytime.