China’s Z.ai put its powerful GLM-5.3 AI model on hold. The decision came after tests showed that the model could handle difficult hacking tasks. The company announced that GLM 5.3 is highly capable of finding and exploiting flaws. Thus, the company is holding the public release by two weeks to strengthen security. The company trained the model specifically to identify vulnerabilities, but it’s also exploiting them. For now, the company has granted limited partners access to the model in controlled settings.
Z.ai is not the only company dealing with this problem. OpenAI and Anthropic have also seen their AI models show strong cyber skills during tests. These models can identify software flaws and assist with certain hacking tasks. The growing abilities have made AI safety a bigger concern. Companies now have to think about what their models can do after release, not just what they were built to do.
AI can help security teams find weak spots before hackers do. The same tools can also be used for the wrong reasons. A model that can write code, find flaws, and complete tasks on its own can be risky in the wrong hands. Z.ai’s decision shows why testing matters. A model may seem safe at first. More tests can reveal abilities that were not expected.
The problem starts when even the developers are not sure how far a model’s abilities can go. In such cases, releasing the weights could create risks that are hard to reverse. GLM-5.3 adds another example to an AI safety debate that is only getting bigger.