What’s Vulnerable › Vulnerabilities

CVE-2026-26220: LightLLM <= 1.1.0 PD Mode Unsafe Deserialization RCE

• Severity: critical (CVSS 9.3 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-17 · updated 2026-07-14
• Weakness: CWE-502

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.

Affected products

• ModelTC LightLLM: through 1.1.0

References

• https://chocapikk.com/posts/2026/lightllm-pickle-rce/
• https://github.com/ModelTC/LightLLM/issues/1213
• 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://lightllm-en.readthedocs.io/en/latest/index.html
• https://www.vulncheck.com/advisories/lightllm-pd-mode-unsafe-deserialization-rce

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