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.
CVE-2026-107204
CRITICALPre-NVD 9.89.8—Trending — 3 sources updated this weekElevated
EchelonGraph scoreHIGH confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-07. A secondary CVSS source baseline 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
9.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.8Exploit: Elevated riskExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
- CVSS v3
- 9.8
- EG Score
- 9.8CRITICALhigh confidence
- EG Risk
- 75EG Risk 75/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity98% × 45%Exploitation40% × 40%Automatability100% × 15%CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 7, 2026
Last Modified
October 7, 2026
Advisory Details (5)
Auto-updated Oct 7, 2026No fix on record yet.
generic
run_script sandbox escape via FastAPI app object in LMCache internal API server (RCE when enabled) · Issue #5510 · LMCache/LMCache · GitHub
https://github.com/LMCache/LMCache/issues/5510generic
LMCache through 0.5.5 Unauthenticated RCE via /run_script Endpoint | Advisories | VulnCheck
https://www.vulncheck.com/advisories/lmcache-through-0.5.5-unauthenticated-rce-via-run-script-endpointgeneric
LMCache/lmcache/v1/multiprocess/http_apis/common_api.py at v0.5.5 · LMCache/LMCache · GitHub
https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/multiprocess/http_apis/common_api.py#L41-L46generic
LMCache/lmcache/v1/internal_api_server/common/run_script_api.py at v0.5.5 · LMCache/LMCache · GitHub
https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/internal_api_server/common/run_script_api.py#L54-L76generic
GitHub - LMCache/LMCache: LMCache: Supercharge Your LLM with the Fastest KV Cache Layer · GitHub
https://github.com/LMCache/LMCacheVendor Advisories for CVE-2026-107204(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-08 01:04 UTCGHSA enrichment
- 2026-10-07 21:12 UTCEG score recompute
- 2026-10-07 21:12 UTCGHSA enrichment
- 2026-10-07 17:19 UTCEG score recompute
- 2026-10-07 16:40 UTCEG score recompute
- 2026-10-07 15:47 UTCEG score recompute
- 2026-10-07 15:46 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-107204?
CVE-2026-107204 is a critical vulnerability published on October 7, 2026. 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…
When was CVE-2026-107204 disclosed?
CVE-2026-107204 was first published on October 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-107204?
CVE-2026-107204 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-107204?
No fix for CVE-2026-107204 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-107204 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-107204
Is Your Infrastructure Affected by CVE-2026-107204?
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