{"id":"GHSA-43rv-jrfh-9mrr","title":"Duplicate Advisory: vm2: NodeVM zlib Buffers expose pooled host memory across the VM boundary","summary":"Duplicate Advisory: vm2: NodeVM zlib Buffers expose pooled host memory across the VM boundary","severity":"medium","cvss":7.5,"cwe":["CWE-200"],"vendor":"vm2","product":"vm2","ecosystem":"npm","affected":["vm2 < 3.12.2"],"patched":["vm2 3.12.2"],"published":"2026-09-27","updated":"2026-10-05","sourceUpdated":"2026-10-05T22:59:46Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-43rv-jrfh-9mrr","references":[{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100723"},{"url":"https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089"},{"url":"https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09"},{"url":"https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool"},{"url":"https://github.com/advisories/GHSA-43rv-jrfh-9mrr"}],"tags":["ghsa","npm"],"ingestedAt":"2026-10-05T23:36:21.170Z","slug":"GHSA-43rv-jrfh-9mrr","body":"## Overview\n\n## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-489w-w794-jq94. This link is maintained to preserve external references.\n\n## Original Description\nvm2 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.\n\n## Affected packages\n\n- `vm2 < 3.12.2`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `vm2 3.12.2`","depth":"sunlit","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}