LMCache Unauthenticated RCE in multiprocess mode via pickle deserialization
Summary
| CVE | CVE-2026-105192 |
|---|---|
| State | PUBLISHED |
| Assigner | JFROG |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-07 10:17:32 UTC |
| Updated | 2026-10-29 11:17:24 UTC |
| Description | LMCache multiprocess mode, also called distributed mode, opens an unauthenticated ZeroMQ ROUTER so worker processes can register and share KV cache blocks. Messages on that socket are msgpack. Extension code 1 is passed to DeviceIPCWrapper.Deserialize, which calls pickle.loads, while the server is still decoding request arguments and 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 transport binds to localhost unless the operator sets a routable address with --host, which is how multi-node deployments let peers connect. The decode path shipped in v0.3.9 and is present through v0.5.5, including the v0.5.6 release candidates. v0.5.6, published on 2026-10-14, removes pickle.loads from this path. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.007720000 probability, percentile 0.556100000 (date 2026-10-29)
Problem Types: CWE-306 | CWE-502 | CWE-502 CWE-502: Deserialization of Untrusted Data | CWE-306 CWE-306: Missing Authentication for Critical Function
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| research.jfrog.com/vulnerabilities/lmcache-is-vulnerable-to-unauthenticated-remo... | [email protected] | research.jfrog.com | |
| github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/platform/base/ipc_wrap... | [email protected] | github.com | |
| github.com/LMCache/LMCache | [email protected] | github.com | |
| github.com/LMCache/LMCache/blob/v0.3.9/lmcache/v1/multiprocess/custom_ty... | [email protected] | github.com | |
| github.com/LMCache/LMCache/releases/tag/v0.5.6 | [email protected] | github.com | |
| github.com/LMCache/LMCache/pull/5684 | [email protected] | github.com | |
| blog.lmcache.ai/en/2026/10/13/an-update-on-cve-2026-105192 | [email protected] | blog.lmcache.ai | |
| github.com/LMCache/LMCache/pull/5685 | [email protected] | github.com | |
| github.com/LMCache/LMCache/pull/5644 | [email protected] | github.com | |
| github.com/LMCache/LMCache/security/advisories/GHSA-w5f2-9q9c-ff4h | [email protected] | github.com | |
| pypi.org/project/lmcache | [email protected] | pypi.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Yuval Moravchick (en)
CNA: JFrog Security Research (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2025-10-29T21:47:00.000Z | LMCache v0.3.9 ships the multiprocess ZMQ transport and the pickle-backed msgpack extension |
| CNA | 2026-10-12T06:22:00.000Z | PR #5644 merged: pickle removed from device IPC descriptors |
| CNA | 2026-10-14T22:21:00.000Z | LMCache v0.5.6 released, the first version that includes the fix |
Solutions
CNA: Upgrade to LMCache 0.5.6 or later. That release replaces pickle in device IPC descriptors with versioned, typed MessagePack descriptors. Descriptors are validated before use, the wrapper type is chosen from a fixed local allowlist, and there is no pickle fallback. The change covers the ZeroMQ and gRPC paths. The wire format changed, so upgrade workers and servers together. The fix is PR #5644 and it is in the v0.5.6 tag. PR #5684, which binds the example Kubernetes deployment to localhost, and PR #5685, which runs the official images as a non-root user, were merged after the v0.5.6 tag was cut and are included in v0.5.7rc2. The v0.5.6 example deployment still passes --host 0.0.0.0, and the v0.5.6 images still run as root.