Vulnerability · Published Jun 12, 2026 · Assigned by GitHub_M

CVE-2026-47210vm2 sandbox escape via JSPI-backed Promise `.finally()` species bypass

Critical 9.8

In plain English

A critical-severity security flaw in vm2 from patriksimek. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.7% (higher than 78% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)1.7%top 22.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, a sandbox escape vulnerability in vm2 allows arbitrary code execution in the host process when untrusted code is executed with async support on runtimes exposing WebAssembly JSPI (WebAssembly.promising / WebAssembly.Suspending). In the tested configuration, a JSPI-backed Promise can reach Promise.prototype.finally() in a way that bypasses the expected Promise-species hardening and exposes a host-originated rejection object to attacker-controlled species logic, breaking the sandbox boundary. This issue has been patched in version 3.11.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	vm2	3.11.4	GHSA-6j2x-vhqr-qr7q

Affected products (as reported)

Vendor	Product	Versions
patriksimek	vm2	< 3.11.4

Weakness: CWE-913 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/patriksimek/vm2/security/advisories/GHSA-6j2x-vhqr-qr7q x_refsource_CONFIRM
https://github.com/patriksimek/vm2/commit/6915fa4d9bcebd47b9a4f39a1adc1aa94ef6ffc6 x_refsource_MISC
https://github.com/patriksimek/vm2/releases/tag/v3.11.4 x_refsource_MISC