# CVE-2026-93603

## Summary

- **CVE ID:** CVE-2026-93603
- **Severity:** CRITICAL
- **CVSS Score:** 10 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H)
- **CWE:** CWE-94
- **Published:** Sep 18, 2026
- **Last Modified:** Sep 18, 2026

## Description

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.

## Affected Products

- patriksimek — vm2 (0)
- patriksimek — vm2 (3.12.1)

## References

- [CNA](https://github.com/patriksimek/vm2/security/advisories/GHSA-j89j-5m6r-cr2q)
- [CNA](https://www.vulncheck.com/advisories/vm2-before-3.12.1-sandbox-escape-rce-via-non-strict-host-function)

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._