Exposure of Resource to Wrong Sphere in vm2 - #VU129588
Published: May 4, 2026
Vulnerability identifier: #VU129588
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-668
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Patrik Simek
Affected software:
vm2
vm2
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information and modify host object state.
The vulnerability exists due to improper isolation in Promise.prototype.then handling in setup-sandbox.js when processing host-side Promise resolutions exposed to the sandbox. A remote attacker can expose a host-side Promise that resolves to a host object and access the resolved value inside a sandbox .then() callback to disclose sensitive information and modify host object state.
Host object identity is preserved across the sandbox boundary, enabling host-side WeakMap or WeakSet identity checks from within the sandbox.
Remediation
Install security update from vendor's website.