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Description

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.

PUBLISHED Reserved 2026-02-11 | Published 2026-02-17 | Updated 2026-02-17 | Assigner VulnCheck




CRITICAL: 9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Problem types

CWE-502 Deserialization of Untrusted Data

Product status

Default status
unknown

Any version
affected

Credits

Valentin Lobstein (Chocapikk) finder

References

chocapikk.com/posts/2026/lightllm-pickle-rce/ technical-description exploit

github.com/ModelTC/LightLLM/issues/1213 issue-tracking patch

lightllm-en.readthedocs.io/en/latest/index.html product

github.com/...0b6fbe20aad66c8fe0/lightllm/server/api_http.py product

github.com/...0b6fbe20aad66c8fe0/lightllm/server/api_http.py product

www.vulncheck.com/...tllm-pd-mode-unsafe-deserialization-rce third-party-advisory

cve.org (CVE-2026-26220)

nvd.nist.gov (CVE-2026-26220)

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