Zhipu releases GLM-5.3, positioned for coding and cyber defense

Chinese AI lab Zhipu (Z.ai) released GLM-5.3 on August 14 through its GLM Coding Plan, calling it the strongest open-weights coding model available and pitching it under the tagline Built to Code, Ready for Cyber Defense. The model builds on the GLM-5.2 base through extended post-training rather than a new pretraining run, and Zhipu says it helped security teams flag 2,436 vulnerabilities across 269 open-source projects, with downloadable weights due to follow after a security review.