{"id":"CVE-2026-100723","revision":"43e66e715a1d444ea02d04ef6f28cef6","records":[{"revision":"43e66e715a1d444ea02d04ef6f28cef6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-100723","aliases":[],"title":"vm2 before 3.12.2 Memory Disclosure via zlib Buffer Pool","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.","state":0,"publishedAt":"2026-09-27T01:28:30.027+00:00","modifiedAt":"2026-10-01T18:04:57.414+00:00","affected":[{"ecosystem":"Vendor product","name":"vm2","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"patriksimek\",\n                    \"product\": \"vm2\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:npm/vm2\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThan\": \"3.12.2\"\n                        },\n                        {\n                            \"version\": \"3.12.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N","score":6.9,"severity":"MEDIUM"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N","score":7.5,"severity":"HIGH"}],"references":["https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94","https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089","https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09","https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-100723","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-100723","identifiers":["CVE-2026-100723"]},"retained":false,"historicalAffected":[]}],"coverage":[]}