CVE-2026-96560: LightLLM through 1.2.0 Unauthenticated Remote Code Execution via NCCL PD RPyC Control Channel

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-23 · updated 2026-09-23
Weakness: CWE-502

Description

LightLLM through 1.2.0 contains a remote code execution vulnerability in the KV-transfer worker when started with --pd_trans_mode nccl, which exposes an unauthenticated RPyC control channel that deserializes attacker-supplied data. Attackers can send malicious pickled objects to the exposed RPyC ThreadedServer to execute arbitrary code with the privileges of the LightLLM service account.

Affected products

ModelTC LightLLM: through 1.2.0

References

https://github.com/ModelTC/LightLLM/issues/1590
https://github.com/ModelTC/lightllm
https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/router/model_infer/mode_backend/pd/kv_transporter.py#L20-L36
https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/router/model_infer/mode_backend/pd/nccl_kv_transporter.py#L247-L249
https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/router/model_infer/mode_backend/pd/nccl_kv_transporter.py#L411-L415
https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/router/model_infer/mode_backend/pd/nccl_kv_transporter.py#L437-L461
https://www.vulncheck.com/advisories/lightllm-through-1.2.0-unauthenticated-remote-code-execution-via-nccl-pd-rpyc-control-channel

Get alerted when CVE-2026-96560 or the next vulnerability affects your stack