Z.ai Releases GLM-5.3: Open-Weight Model Outscores Anthropic and OpenAI on CyberGym
Chinese AI company Z.ai has released GLM-5.3, an open-weight model that scored 84.5% on the CyberGym cybersecurity benchmark, beating Anthropic’s Mythos 5 and OpenAI’s GPT-5.6 Sol. Built on the same base as GLM-5.2 with all gains from scaled post-training, it also set an open-source record on Terminal Bench 3.0 and unexpectedly acquired exploit-chain reasoning, uncovering 1,097 critical vulnerabilities in Linux, WebKit and FreeBSD. Weights open within two weeks.
