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Findings

Vulnerability · CVE-2026-105192

LMCache: Remote code execution via unsafe deserialization in multiprocess mode transport

Published Oct 16, 2026 · corrected/updated Oct 16, 2026 · evidence confidence high

### Summary LMCache is vulnerable to Unauthenticated Remote Code Execution via Pickle Deserialization on the Multiprocess ZMQ Transport ### Details LMCache multiprocess mode, also called distributed mode, opens an unauthenticated ZeroMQ ROUTER so worker processes can register and share KV cache blocks. The intended clients are sibling LMCache processes. There is no CURVE, ZAP, password, or message authentication on that socket. LMCache used only inside a vLLM process does not open this port. The transport binds to localhost unless the operator sets a routable address with --host, which is how multi-node deployments let peers connect. The 9.8 score is for that routable configuration. A stock single-host install that leaves the default bind is not reachable from other machines. Messages on the socket are msgpack. Extension code 1 is registered for DeviceIPCWrapper and is passed to DeviceIPCWrapper.Deserialize in lmcache/v1/platform/base/ipc_wrapper.py, which calls pickle.loads. That hook runs from ext_hook in lmcache/v1/multiprocess/custom_types.py while the server is still decoding REGISTER_KV_CACHE arguments, before the handler runs. A single unauthenticated ZMQ DEALER message to the transport port (default 5555) therefore executes code as the user the LMCache process runs as. Official container images run that process as root. The decode path shipped in v0.3.9. It is still present in the latest PyPI release, v0.5.5, in the v0.5.6 release candidates through v0.5.6rc3, and on the dev branch as of 2026-10-07. No fixed version has been published. ### Proof of concept Step 1 - Start multiprocess mode bound to a routable address This is the documented multi-node setting. The ZMQ transport listens on port 5555. Step 2 - Build a REGISTER_KV_CACHE frame whose cache slot is a pickle Payload slot 1 is a msgpack extension with code 1. The server unpickles that body while it is still decoding arguments. The command writes id to /tmp/zmq_pwn. Step 3 - Send the frame The pickle r

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-105192 is a critical public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: lmcache (0.3.9 → 0.5.6); lmcache (>= 0.3.9, < 0.5.6). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 9.8, EPSS 0.5%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-306. Sources contributing to this record: epss, github, osv, pypa. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 16, 2026 · GitHub Advisory Database

    Detected

    ### Summary LMCache is vulnerable to Unauthenticated Remote Code Execution via Pickle Deserialization on the Multiprocess ZMQ Transport ### Details LMCache multiprocess mode, also called distributed mode, opens an unauthenticated ZeroMQ ROUTER so worker processes can register and share KV cache blocks. The intended clients are sibling LMCache processes. There is no CURVE, ZAP, password, or message

  2. Oct 16, 2026 · GitHub Advisory Database

    Fix available

    lmcache fixed in 0.5.6

  3. Oct 16, 2026 · GitHub Advisory Database

    Fix available

    lmcache fixed in 0.5.6

  4. Oct 16, 2026 · GitHub Advisory Database

    Updated

    ### Summary LMCache is vulnerable to Unauthenticated Remote Code Execution via Pickle Deserialization on the Multiprocess ZMQ Transport ### Details LMCache multiprocess mode, also called distributed mode, opens an unauthenticated ZeroMQ ROUTER so worker processes can register and share KV cache blocks. The intended clients are sibling LMCache processes. There is no CURVE, ZAP, password, or message

Affected

  • PyPI lmcache0.3.9 → 0.5.6
  • pip lmcache>= 0.3.9, < 0.5.6

Sources

References