{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-71920", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-08-08T16:37:44.518Z", "datePublished": "2026-08-24T17:07:50.273Z", "dateUpdated": "2026-08-24T17:07:50.273Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-08-24T17:07:50.273Z"}, "datePublic": "2026-08-24T00:00:00.000Z", "title": "DrayTek VigorSwitch Multiple Models NULL Pointer Dereference via formlogout", "descriptions": [{"lang": "en", "value": "Multiple DrayTek VigorSwitch models contain a null pointer dereference vulnerability in the formlogout function. The vulnerability is caused by missing checks for an empty or absent Cookie header before string handling. A remote attacker can trigger this vulnerability via a crafted request to crash the service and cause a denial of service. Exploitation requires valid administrative credentials for the device's web management interface."}], "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-476", "description": "NULL Pointer Dereference", "type": "CWE"}]}], "affected": [{"vendor": "DrayTek Corporation", "product": "VigorSwitch G2540xs", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "3.9.10", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2540xs", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "3.9.10", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch FX2120", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "3.9.10", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2282x", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "2.10.6", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2282x", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "2.10.6", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch Q2300x", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "2.10.7", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch PQ2300xb", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "2.10.7", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2542x", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": "3.10.6", "status": "affected", "versionType": "custom"}]}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2542x", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThan": 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"baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}}], "references": [{"url": "https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/", "tags": ["vendor-advisory"]}, {"name": "VulnCheck Advisory: DrayTek VigorSwitch Multiple Models NULL Pointer Dereference via formlogout", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-null-pointer-dereference-via-formlogout"}], "credits": [{"lang": "en", "value": "Jincheng Wang (@winmt)", "type": "finder"}, {"lang": "en", "value": "Le Yu (Nanjing University of Posts and Telecommunications)", "type": "finder"}, {"lang": "en", "value": "Xiapu Luo (The Hong Kong Polytechnic University)", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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