What’s Vulnerable › Vulnerabilities

CVE-2026-47135: vm2: Sandbox escape via unblocked cross-realm Symbol.for keys + missing bridge write-trap symbol checks

• Severity: high (CVSS 8.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-12 · updated 2026-10-26
• Weakness: CWE-693

Description

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, Symbol.for override in setup-sandbox.js only intercepts 2 of 9 dangerous Node.js cross-realm symbols. Combined with the bridge's set/defineProperty/deleteProperty traps having no isDangerousCrossRealmSymbol key check, sandbox code can obtain real cross-realm symbols, write them to host objects, and control host-side behavior — verified with a full util.promisify hijack chain. This issue has been patched in version 3.11.4.

Affected products

• patriksimek vm2: before 3.11.4

References

• https://github.com/patriksimek/vm2/commit/928aef51898b5c52a05f05a40c4cfeb52e172878
• https://github.com/patriksimek/vm2/releases/tag/v3.11.4
• https://github.com/patriksimek/vm2/security/advisories/GHSA-m5q2-4fm3-vfqp

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