CVE-2026-96560 Details

A remote code execution vulnerability has been identified in LightLLM versions through 1.2.0. The issue arises in the KV-transfer worker when the application is run with the '--pd_trans_mode nccl' option. This configuration exposes an unauthenticated RPyC control channel that allows for the deserialization of attacker-supplied data. Exploitation involves sending malicious pickled objects to the exposed RPyC ThreadedServer, which executes arbitrary code under the privileges of the LightLLM service account.

To address this vulnerability, remove the 'allow_pickle', 'allow_all_attrs', 'allow_getattr', and 'allow_setattr' options from the RPyC ThreadedServer protocol configuration. Instead, use RPyC's restricted defaults and pass plain validated structures. Additionally, authenticate the control channel, such as by using a shared secret distributed via the config server or mutual TLS.