Anthropic warns China’s GLM-5.3 open model poses serious cyberattack risk

A Frontier Red Team report says Z.ai's freely downloadable model builds exploits nearly as well as Claude Mythos Preview, and its guardrails peel off cheaply Anthropic has a problem with a model it didn’t build. On September 29, 2026, the company’s Frontier Red Team published a report arguing that GLM-5.3, an open-weight model from Chinese AI lab Z.ai, represents a major cyberattack risk. The concern is less about what the model can do and more about who gets to do it. Anyone can download GLM-5.3, modify it, and run it without asking permission. The headline number is exploit generation.

BeCrypto News shows a short excerpt and links to the publisher. The full report belongs to Crypto Briefing.