Chinese AI company Z.ai targets Anthropic’s Claude Mythos

Chinese artificial intelligence (AI) startup Zhipu AI, or Z.ai, has released an open-weight GLM-5.2 model that matches Anthropic’s controversial Mythos class-model in cybersecurity and software vulnerability identification tasks. Researchers who have tested and compared frontier models say the Chinese AI company continues to have a significant cost advantage, first illustrated by DeepSeek early last year.

American cybersecurity company Semgrep, using the IDOR (Insecure Direct Object Reference) benchmark that tests for a specific vulnerability where an application exposes an internal identifier such as a user ID without permission, noted that GLM-5.2 scored higher (39%) than Anthropic’s Claude Opus 4.6(32%) and Claude Opus 4.8/4.7 (28%).