Protection Mechanism Failure in vm2 - #VU131738
Published: May 18, 2026
Vulnerability identifier: #VU131738
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: N/A
CWE-ID: CWE-693
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 modify host-side behavior and disclose sensitive information.
The vulnerability exists due to protection mechanism failure in setup-sandbox.js and bridge.js when processing cross-realm Symbol.for keys and symbol-keyed property operations. A remote attacker can obtain unblocked cross-realm symbols and write them to host objects to modify host-side behavior and disclose sensitive information.
This can affect non-frozen host objects exposed to the sandbox and was demonstrated through a util.promisify hijack chain.
Remediation
Install security update from vendor's website.