Cross-request KV cache exposure in the GLM-5.3 Workers AI model, and our remediation with SGLang

Cloudflare reports that from August 27 to September 9, 2026, 155 responses from the GLM-5.3 Workers AI model (@cf/zai-org/glm-5.3) to prompts longer than 681,280 tokens contained data from other customers' requests, caused by a prefill KV pool smaller than the 1,048,576-token context window combined with an SGLang bug that let rejected over-length requests proceed through disaggregated prefill/decode handoff. The model was taken offline on September 9 and restored the same day after a corrected configuration and an engine patch, and Cloudflare says it found no evidence of deliberate exploitation. Cloudflare recommends operators of disaggregated SGLang upgrade to v0.5.22 or later and verify KV pool size against context length on every node.