CVE-2026-26220 PUBLISHED

LightLLM version 1.1.0 and prior contain an unauthenticated remote code execution vulnerability in PD (prefill-decode) disaggregation mode. The PD master node exposes WebSocket endpoints that receive binary frames and pass the data directly to pickle.loads() without authentication or validation. A remote attacker who can reach the PD master can send a crafted payload to achieve arbitrary code execution.

• Valentin Lobstein (Chocapikk) finder

• https://chocapikk.com/posts/2026/lightllm-pickle-rce/
• https://github.com/ModelTC/LightLLM/issues/1213
• https://lightllm-en.readthedocs.io/en/latest/index.html
• https://github.com/ModelTC/lightllm/blob/a27dfc88c2144ed51a6e160b6fbe20aad66c8fe0/lightllm/server/api_http.py#L310
• https://github.com/ModelTC/lightllm/blob/a27dfc88c2144ed51a6e160b6fbe20aad66c8fe0/lightllm/server/api_http.py#L331
• https://www.vulncheck.com/advisories/lightllm-pd-mode-unsafe-deserialization-rce

• CWE-502 Deserialization of Untrusted Data CWE