LMDeploy deserializes disaggregated-serving peer messages with pickle. The handle_zmq_recv coroutine in lmdeploy/pytorch/disagg/conn/engine_conn.py reads peer-to-peer cache-free requests with recv_pyobj(), which deserializes the received bytes with pickle.loads(), and the isinstance check against DistServeCacheFreeRequest runs only after deserialization has already completed. The peer that supplies those bytes is caller-controlled: p2p_connect passes remote_engine_endpoint_info.zmq_address from the request body to connect() on the ZMQ PULL socket, and the POST /distserve/p2p_initialize and /distserve/p2p_connect endpoints in lmdeploy/serve/openai/api_server.py apply no authentication unless the server is started with api_keys, which defaults to None. A remote attacker can direct an engine to pull from a ZMQ endpoint under their control and execute arbitrary code in the engine process. Deployments that do not enable disaggregated serving are not affected, because the receive loop is only started once the migration backend accepts the connection.
Advisories
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Fixes
Solution
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Workaround
No workaround given by the vendor.
References
History
Wed, 19 Aug 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | LMDeploy deserializes disaggregated-serving peer messages with pickle. The handle_zmq_recv coroutine in lmdeploy/pytorch/disagg/conn/engine_conn.py reads peer-to-peer cache-free requests with recv_pyobj(), which deserializes the received bytes with pickle.loads(), and the isinstance check against DistServeCacheFreeRequest runs only after deserialization has already completed. The peer that supplies those bytes is caller-controlled: p2p_connect passes remote_engine_endpoint_info.zmq_address from the request body to connect() on the ZMQ PULL socket, and the POST /distserve/p2p_initialize and /distserve/p2p_connect endpoints in lmdeploy/serve/openai/api_server.py apply no authentication unless the server is started with api_keys, which defaults to None. A remote attacker can direct an engine to pull from a ZMQ endpoint under their control and execute arbitrary code in the engine process. Deployments that do not enable disaggregated serving are not affected, because the receive loop is only started once the migration backend accepts the connection. | |
| Title | LMDeploy Remote Code Execution via Unsafe Pickle Deserialization in the Disaggregated Serving Peer Connector | |
| First Time appeared |
Internlm
Internlm lmdeploy |
|
| Weaknesses | CWE-502 | |
| CPEs | cpe:2.3:a:internlm:lmdeploy:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Internlm
Internlm lmdeploy |
|
| References |
|
|
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-08-19T21:41:28.068Z
Reserved: 2026-08-19T21:24:37.594Z
Link: CVE-2026-76850
No data.
Status : Received
Published: 2026-08-19T22:17:28.123
Modified: 2026-08-19T22:17:28.123
Link: CVE-2026-76850
No data.
OpenCVE Enrichment
No data.
Weaknesses