{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-100723", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-26T02:40:56.226Z", "datePublished": "2026-09-27T01:28:30.027Z", "dateUpdated": "2026-09-27T01:28:30.027Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-27T01:28:30.027Z"}, "datePublic": "2026-09-08T00:00:00.000Z", "title": "vm2 before 3.12.2 Memory Disclosure via zlib Buffer Pool", "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Exposure of Sensitive Information to an Unauthorized Actor", "cweId": "CWE-200", "type": "CWE"}]}], "affected": [{"vendor": "patriksimek", "product": "vm2", "defaultStatus": "unaffected", "packageURL": "pkg:npm/vm2", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "3.12.2"}, {"version": "3.12.2", "status": "unaffected", "versionType": "semver"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "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", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-489w-w794-jq94)"}, {"url": "https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089", "tags": ["patch"], "name": "Patch Commit"}, {"url": "https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09", "tags": ["patch"], "name": "Patch Commit"}, {"name": "VulnCheck Advisory: vm2 before 3.12.2 Memory Disclosure via zlib Buffer Pool", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool"}], "credits": [{"lang": "en", "value": "rexpository", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/vm2", "product": "vm2", "vendor": "patriksimek", "versions": [{"lessThan": "3.12.2", "status": "affected", "version": "0", "versionType": "semver"}, {"status": "unaffected", "version": "3.12.2", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-100723", "lastModified": "2026-09-27T02:17:20.553", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.7, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-09-27T02:17:19.373", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-200"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.12.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "3.12.2"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "vm2", "source": "cna", "vendor": "patriksimek"}, "product": "vm2", "vendor": "patriksimek"}], "created": "2026-09-27T03:30:20.605024+00:00", "updated": "2026-09-27T05:00:07.689520+00:00", "vendors": ["patriksimek", "patriksimek$PRODUCT$vm2"]}