vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. (CVE-2026-100722)
vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. In BaseHandler, the apply trap calls markHostPromiseHandled() on the returned value, but the adjacent construct path returns the result of Reflect.construct without the same sanitization. If an embedder exposes a constructable host function whose constructor returns a native rejected Promise, an untrusted script executed via VM.run can invoke it with `new` and ignore the result; the rejected host Promise crosses the bridge unhandled and, under Node's strict unhandled-rejection policy, is promoted to an uncaught exception that terminates the host process.
AI Analysis
Technical Summary
The vm2 sandbox before version 3.12.2 does not properly handle host-side Promise rejections in the construct trap used when sandboxed code invokes host functions with the 'new' operator. While the apply trap sanitizes returned Promises by marking them as handled, the construct trap returns the result of Reflect.construct without this sanitization. If a host function's constructor returns a native rejected Promise, the rejection crosses the sandbox boundary unhandled. Under Node.js's strict unhandled rejection policy, this leads to an uncaught exception that terminates the host process.
Potential Impact
Exploitation of this vulnerability can cause the host Node.js process to terminate unexpectedly due to unhandled Promise rejections originating from sandboxed code invoking certain host functions. This results in a denial of service condition. There is no direct impact on confidentiality or integrity reported.
Mitigation Recommendations
A fix is available in vm2 version 3.12.2 that applies proper host-side Promise rejection handling in the construct trap. Users should upgrade to vm2 3.12.2 or later to remediate this issue. No other mitigation steps are indicated.
vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. (CVE-2026-100722)
Description
vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. In BaseHandler, the apply trap calls markHostPromiseHandled() on the returned value, but the adjacent construct path returns the result of Reflect.construct without the same sanitization. If an embedder exposes a constructable host function whose constructor returns a native rejected Promise, an untrusted script executed via VM.run can invoke it with `new` and ignore the result; the rejected host Promise crosses the bridge unhandled and, under Node's strict unhandled-rejection policy, is promoted to an uncaught exception that terminates the host process.
CVSS v3.1
Score 6.8medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vm2 sandbox before version 3.12.2 does not properly handle host-side Promise rejections in the construct trap used when sandboxed code invokes host functions with the 'new' operator. While the apply trap sanitizes returned Promises by marking them as handled, the construct trap returns the result of Reflect.construct without this sanitization. If a host function's constructor returns a native rejected Promise, the rejection crosses the sandbox boundary unhandled. Under Node.js's strict unhandled rejection policy, this leads to an uncaught exception that terminates the host process.
Potential Impact
Exploitation of this vulnerability can cause the host Node.js process to terminate unexpectedly due to unhandled Promise rejections originating from sandboxed code invoking certain host functions. This results in a denial of service condition. There is no direct impact on confidentiality or integrity reported.
Mitigation Recommendations
A fix is available in vm2 version 3.12.2 that applies proper host-side Promise rejection handling in the construct trap. Users should upgrade to vm2 3.12.2 or later to remediate this issue. No other mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-7rr2-8fr3-fjqx
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-100722"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6ab89bc3f7a7c54106941edd
Added to database: 09/27/2026, 04:29:55 UTC
Last enriched: 09/27/2026, 04:36:46 UTC
Last updated: 09/28/2026, 01:59:12 UTC
Views: 6
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