CVE-2026-93603

CRITICALPre-NVD 10.010.0—
EchelonGraph scoreHIGH confidence

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-18. a secondary CVSS source baseline 10.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
10.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 10.0Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

vm2 through 3.12.0 (fixed in 3.12.1) does not correctly handle a nullish this receiver in the apply trap of its bridge (lib/bridge.js): when sandboxed code calls a host-provided non-strict (sloppy-mode) function without a receiver — e.g. fn(), a detached method, fn.call(), fn.apply(undefined), Reflect.apply(fn, undefined, []), or fn.bind()() — the undefined receiver is passed straight through to the host call, and V8 substitutes the host realm's global object for this. vm2 then wraps and returns that object to the sandbox, giving sandboxed script a live proxy of the host global. This allows a complete sandbox escape: untrusted script can reach process and execute arbitrary code/commands on the host (for example via process.getBuiltinModule('child_process').execSync). Exploitation requires that the embedding application expose at least one non-strict host function to the sandbox; strict-mode and ES module host functions are not affected.

CVSS v3
10.0
EG Score
10.0(high)
EG Risk
50(Track)
EG Risk 50/100SSVC: Track

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 computed
Severity100% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

September 18, 2026

Last Modified

September 18, 2026

Advisory Details (2)

Auto-updated Sep 18, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

vm2 before 3.12.1 Sandbox Escape RCE via Non-Strict Host Function | Advisories | VulnCheck

https://www.vulncheck.com/advisories/vm2-before-3.12.1-sandbox-escape-rce-via-non-strict-host-function
github Patch Available🟡 PoC Available

Sandbox escape to host RCE via nullish this-receiver on non-strict host function · Advisory · patriksimek/vm2 · GitHub

https://github.com/patriksimek/vm2/security/advisories/GHSA-j89j-5m6r-cr2q

Vendor Advisories for CVE-2026-93603(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 14× in last 7d / 14× 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.

  1. 2026-09-20 01:43 UTCGHSA enrichment
  2. 2026-09-19 21:48 UTCGHSA enrichment
  3. 2026-09-19 17:53 UTCEG score recompute
  4. 2026-09-19 17:53 UTCGHSA enrichment
  5. 2026-09-19 13:57 UTCGHSA enrichment
  6. 2026-09-19 09:58 UTCGHSA enrichment
  7. 2026-09-19 06:03 UTCGHSA enrichment
  8. 2026-09-19 02:07 UTCGHSA enrichment
  9. 2026-09-18 22:11 UTCGHSA enrichment
  10. 2026-09-18 18:16 UTCEG score recompute
  11. 2026-09-18 18:16 UTCGHSA enrichment
  12. 2026-09-18 14:21 UTCEG score recompute
  13. 2026-09-18 13:29 UTCEG score recompute
  14. 2026-09-18 13:29 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-93603?
CVE-2026-93603 is a critical vulnerability published on September 18, 2026. vm2 through 3.12.0 (fixed in 3.12.1) does not correctly handle a nullish this receiver in the apply trap of its bridge (lib/bridge.js): when sandboxed code calls a host-provided non-strict (sloppy-mode) function without a receiver — e.g. fn(), a detached method, fn.call(), fn.apply(undefined),…
When was CVE-2026-93603 disclosed?
CVE-2026-93603 was first published in the National Vulnerability Database on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93603 actively exploited?
CVE-2026-93603 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.5% of all scored CVEs.
What is the CVSS score of CVE-2026-93603?
CVE-2026-93603 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2026-93603?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-93603, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-93603

Explore →

Is Your Infrastructure Affected by CVE-2026-93603?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs