Cloudflare discloses cross-customer data exposure on Workers AI, traced to an SGLang bug
Cloudflare says 155 responses from the GLM-5.3 model on Workers AI between Aug 27 and Sep 9 contained data from other customers' requests, all for prompts over 681,280 tokens. A mismatch between the context window and the KV cache pool triggered a bug in SGLang's disaggregated prefill/decode mode. Cloudflare says it found no evidence of deliberate exploitation; SGLang published a coordinated fix.
Why it matters: Engines often reuse KV cache pages across requests; an ownership bug in disaggregated serving can leak one user's data into another's reply. Cloudflare urges SGLang operators to match KV pool size to context length and upgrade to v0.5.22+.
