CVE-2026-107204: LMCache through 0.5.5 Unauthenticated RCE via /run_script Endpoint

Q: Who can exploit this vulnerability?

A remote attacker can exploit it without authentication or user interaction if they can reach the LMCache /run_script endpoint over the network.

Q: What level of access can an attacker gain?

An attacker can execute Python code and operating-system commands as the LMCache process. This can affect confidentiality, integrity, and availability at the privilege level of that process.

Q: Which LMCache versions are affected?

The issue is reported in LMCache through version 0.5.5. The provided data does not identify a fixed version.

Q: How can I determine whether an instance is exposed?

Check whether the deployment runs LMCache 0.5.5 or an earlier version and whether its /run_script endpoint is reachable by untrusted remote clients. Exploitation does not require credentials.

Published Oct 7, 2026

Updated

LMCache through 0.5.5 contains an unauthenticated remote code execution vulnerability that allows remote attackers to execute Python code by posting scripts to the /runscript endpoint. Attackers can recover real builtins through the injected FastAPI app object, bypassing the guarded import, to import os and run operating system commands as the LMCache process.

Affected Software

1 affected component

pypi/lmcache<=0.5.5

Event History

Oct 7, 2026

CVE Published

via MITRE·03:24 PM

Data Sourced

via MITRE·03:24 PM

DescriptionSeverityWeakness

Data Sourced

via NVD·04:17 PM

DescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this vulnerability?

A remote attacker can exploit it without authentication or user interaction if they can reach the LMCache /run_script endpoint over the network.

What level of access can an attacker gain?

An attacker can execute Python code and operating-system commands as the LMCache process. This can affect confidentiality, integrity, and availability at the privilege level of that process.

Which LMCache versions are affected?

The issue is reported in LMCache through version 0.5.5. The provided data does not identify a fixed version.

How can I determine whether an instance is exposed?

Check whether the deployment runs LMCache 0.5.5 or an earlier version and whether its /run_script endpoint is reachable by untrusted remote clients. Exploitation does not require credentials.

CVE-2026-107204: LMCache through 0.5.5 Unauthenticated RCE via /run_script Endpoint

Affected Software

Event History

Frequently Asked Questions

Who can exploit this vulnerability?

What level of access can an attacker gain?

Which LMCache versions are affected?

How can I determine whether an instance is exposed?

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Frequently Asked Questions

Who can exploit this vulnerability?

What level of access can an attacker gain?

Which LMCache versions are affected?

How can I determine whether an instance is exposed?