vm2: Bridge Proxy set trap ignores receiver parameter, enabling host object property injection via prototype chain (patriksimek vm2)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.29 % · percentile 21 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Deferred
Description
vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, the BaseHandler.set trap in bridge.js (line 1231) ignores the receiver parameter and unconditionally writes to the host target object. Per the Proxy set trap specification, when receiver !== proxy (e.g., when a child object inherits from the proxy via Object.create), the property assignment should create an own property on the receiver, not on the proxy target. The current implementation always calls otherReflectSet(object, key, value) against the host target, causing all inherited property writes to leak through to the host object. This bug provides an alternative attack vector for writing dangerous cross-realm Symbol keys (e.g., nodejs.util.promisify.custom) to host objects, bypassing any future per-trap isDangerousCrossRealmSymbol guard on the direct set path. This issue has been patched in version 3.11.4.
Weaknesses (CWE)
- CWE-693 — Protection Mechanism Failure
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N | GitHub_M |
| CVSS 3.1 | HIGH 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-c4cf-2hgv-2qv6 — vm2's Bridge Proxy set trap ignores receiver parameter, enabling host object property injection via prototype chain
European references
- ENISA EUVD · EUVD-2026-36440
- GCVE · GCVE-0-2026-47209
Affected products
| Product | Versions |
|---|---|
| patriksimek · vm2 | affected < 3.11.4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |