{"id":"CVE-2026-100723","summary":"vm2 before 3.12.2 Memory Disclosure via zlib Buffer Pool","details":"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.","aliases":["GHSA-489w-w794-jq94"],"modified":"2026-09-28T03:48:31.533094183Z","published":"2026-09-27T01:28:30.027Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-200"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100723.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100723.json"},{"type":"ADVISORY","url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100723"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool"},{"type":"FIX","url":"https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089"},{"type":"FIX","url":"https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/patriksimek/vm2","events":[{"introduced":"0"},{"fixed":"a0139cf6a7ad72a685420f53479a99fe385cf394"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"3.12.2"}]}}],"versions":["v3.12.1","v3.12.0","v3.11.8","v3.11.7","3.11.6","v3.11.5","v3.11.4","v3.11.3","v3.11.2","v3.11.1","v3.11.0","v3.10.5","v3.10.4","v3.10.3","v3.10.2","v3.10.1","v3.10.0","3.9.19","3.9.18","3.9.17","3.9.16","3.9.15","3.9.14","3.9.13","3.9.12","3.9.11","3.9.10","3.9.9","3.9.8","3.9.7","3.9.6","3.9.5","3.9.4","3.9.3","v3.9.2","v3.9.1","v3.9.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100723.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}