CVE-2026-26220

CRITICAL

LightLLM <=1.1.0 - Unauthenticated RCE

Title source: llm

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.

References (6)

[Various Sources] https://chocapikk.com/posts/2026/lightllm-pickle-rce/

[Various Sources] https://github.com/ModelTC/lightllm/blob/a27dfc88c2144ed51a6e160b6fbe20aad66c8fe0/lightllm/server/api_http.py#L310

[Various Sources] https://github.com/ModelTC/lightllm/blob/a27dfc88c2144ed51a6e160b6fbe20aad66c8fe0/lightllm/server/api_http.py#L331

View Writeup ZIP pw:eip

[Various Sources] https://lightllm-en.readthedocs.io/en/latest/index.html

[Third Party Advisory] https://www.vulncheck.com/advisories/lightllm-pd-mode-unsafe-deserialization-rce

[Issue Tracking] https://github.com/ModelTC/LightLLM/issues/1213

Scores

CVSS v4 9.3

EPSS 0.0082

EPSS Percentile 74.5%

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

Details

CWE

CWE-502

Status published

Products (1)

ModelTC/LightLLM < 1.1.0

Published Feb 17, 2026

Tracked Since Feb 18, 2026