Duplicate Advisory: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM
## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2. This link is maintained to preserve external references. ## Original Description vm2 before 3.11.8 does not fully enforce the allowAsync: false option in VM and NodeVM. While localPromise.prototype.then is replaced with a handler that throws 'Async not available', the sandbox's Promise static methods (Promise.resolve, Promise.all, Promise.race, Promise.any, and Promise.allSettled) still assimilate attacker-supplied thenables: native promise resolution performs PromiseResolveThenableJob and invokes the sandboxed code's then method in a microtask without passing through the patched then, so the async restriction is never applied. As a result, sandboxed script can schedule work that runs after VM.run() or NodeVM.run() has returned and outside the configured timeout, continuing to execute after the host believes execution is complete.
GHSA-9538-79j2-h62h
Primary source · Revision 1 · Withdrawn
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-9538-79j2-h62h
vm2
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"last_affected": "3.11.7"
}
]
}
],
"package": {
"name": "vm2",
"purl": "pkg:npm/vm2",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-9538-79j2-h62h/GHSA-9538-79j2-h62h.json"
}
}
]Publisher severity
high
Source reference: /database_specific/severity
- Event
- #85857 · Revision 1
- Added to Heist Feed
- Publisher date