TLDR Tech / InfoSec
LightLLM: Unauthenticated RCE via Pickle Deserialization in WebSocket Endpoints
A critical unauthenticated RCE vulnerability (CVE-2026-26220, CVSS 9.3) has been revealed in LightLLM, a widely used LLM inference engine with 3,890 GitHub stars. The flaw involves WebSocket endpoints in the prefill-decode disaggregation system calling pickle.loads() on unauthenticated binary frames, and the server code explicitly disallows binding to localhost, exposing the server to network threats by design. This vulnerability mirrors CVE-2025-32444 (CVSS 10.0) in vLLM and underscores a broader issue of insecure deserialization across ML inference frameworks, as disaggregated serving architectures create additional attack surfaces between nodes. Organizations using LightLLM in PD mode should immediately restrict network access to WebSocket endpoints, as the maintainers have largely ignored security reports for nearly a year without providing a fix.
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