Building on GLM-5.2’s contributions to cyber defense, GLM-5.3 delivers substantially stronger capabilities in vulnerability discovery, exploit analysis, and complex, multistep security tasks in realistic environments. These advances can help defenders identify weaknesses earlier, validate mitigations, and respond more effectively to emerging threats. Select partners now have access under strict safeguards. Broader access and API availability will follow rigorous safety and security evaluations. We intend to release GLM-5.3 as an open-weight model once those evaluations are complete and appropriate safeguards are in place. We are working with independent security experts and leading institutions to assess these risks, strengthen safeguards, and determine an appropriate path forward.