{"id":"CVE-2026-100723","published":"2026-09-27T02:17:19.373","lastModified":"2026-09-27T02:17:20.553","description":"vm2 before 3.12.2 does not apply its Buffer backing-store ownership invariant (byteOffset === 0 and buffer.byteLength === length) to Buffers returned from host builtin modules. When an application explicitly exposes Node's zlib module through NodeVM's builtin allowlist (require: { builtin: ['zlib'] }), zlib.deflateSync can return a Buffer backed by Node's shared small-buffer pool whose .buffer is the entire pool. Untrusted guest code can construct a full-width view of that ArrayBuffer (Buffer.from(result.buffer, 0, result.buffer.byteLength)) to read and modify bytes belonging to unrelated host buffers, disclosing and corrupting host-realm memory across the sandbox boundary.","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N","cwes":["CWE-200"],"vendors":[],"products":[],"references":[{"url":"https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089","tags":[]},{"url":"https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09","tags":[]},{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94","tags":[]},{"url":"https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool","tags":[]}],"exploitRefs":[{"url":"https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089","tags":[]},{"url":"https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09","tags":[]},{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94","tags":[]}],"hasPoc":true,"ai":null}