{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-3870", "assignerOrgId": "96e50032-ad0d-4058-a115-4d2c13821f9f", "state": "PUBLISHED", "assignerShortName": "Zyxel", "dateReserved": "2026-03-10T08:42:15.293Z", "datePublished": "2026-06-02T01:54:49.100Z", "dateUpdated": "2026-06-02T01:54:49.100Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "96e50032-ad0d-4058-a115-4d2c13821f9f", "shortName": "Zyxel", "dateUpdated": "2026-06-02T01:54:49.100Z"}, "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-120", "description": "CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')", "type": "CWE"}]}], "affected": [{"vendor": "Zyxel", "product": "VMG4005-B50B firmware", "versions": [{"status": "affected", "version": "<= 5.13(ABRL.5.4)C0"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "A buffer overflow vulnerability in the UPnP AddPortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "A buffer overflow vulnerability in the UPnP AddPortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device."}]}], "references": [{"url": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-buffer-overflow-vulnerabilities-in-the-upnp-function-of-certain-4g-lte-5g-nr-cpe-and-dsl-ethernet-cpe-06-02-2026", "tags": ["vendor-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseSeverity": "MEDIUM", "baseScore": 6.5, "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.2"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "A buffer overflow vulnerability in the UPnP AddPortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device."}], "id": "CVE-2026-3870", "lastModified": "2026-06-02T03:16:16.890", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "security@zyxel.com.tw", "type": "Primary"}]}, "published": "2026-06-02T03:16:16.890", "references": [{"source": "security@zyxel.com.tw", "url": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-buffer-overflow-vulnerabilities-in-the-upnp-function-of-certain-4g-lte-5g-nr-cpe-and-dsl-ethernet-cpe-06-02-2026"}], "sourceIdentifier": "security@zyxel.com.tw", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-120"}], "source": "security@zyxel.com.tw", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "<= 5.13(ABRL.5.4)C0"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "VMG4005-B50B firmware", "source": "cna", "vendor": "Zyxel"}, "product": "vmg4005-b50b_firmware", "vendor": "zyxel"}], "created": "2026-06-02T03:30:26.147400+00:00", "title": "Upnp AddPortMapping Buffer Overflow Causes Temporary Denial of Service in Zyxel VMG4005-B50B", "updated": "2026-06-02T04:00:11.900395+00:00", "vendors": ["zyxel", "zyxel$PRODUCT$vmg4005-b50b_firmware"]}