Vulnerability · Published Oct 7, 2026 · Assigned by VulnCheck
CVE-2026-107204LMCache through 0.5.5 Unauthenticated RCE via /run_script Endpoint
Critical 9.8
In plain English
A critical-severity missing authentication in LMCache from LMCache. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities).
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.8%top 44.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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 /run_script 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 products (as reported)
Weakness: CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- GitHub Issue #5510 issue-tracking
- https://github.com/LMCache/LMCache product
- https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/internal_api_server/common/run_script_api.py#L54-L76 technical-description
- https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/multiprocess/http_apis/common_api.py#L41-L46 technical-description
- VulnCheck Advisory: LMCache through 0.5.5 Unauthenticated RCE via /run_script Endpoint third-party-advisory