CVE-2026-71937

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the poe_schedule_profile function. The vulnerability is caused by repeated concatenation of the start_date, start_time, duration_time, how_often, weekdays, monthly_date, and cycle_duration fields into small fixed-size buffers without proper length checks. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device's web management interface.

CVSS v3 7.2 HIGH

7.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/
https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-buffer-overflow-via-poe-schedule-profile

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-24 18:17

Updated : 2026-08-26 17:08

NVD link : CVE-2026-71937

Mitre link : CVE-2026-71937

CVE.ORG link : CVE-2026-71937

JSON object : View

Products Affected

No product.

CWE

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

{"id": "CVE-2026-71937", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-71937", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-08-24T18:44:16.323310Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.2, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "HIGH", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.2}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.6, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "DrayTek Corporation", "product": "VigorSwitch G2540xs", "versions": [{"status": "affected", "version": "0", "lessThan": "3.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2540xs", "versions": [{"status": "affected", "version": "0", "lessThan": "3.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch FX2120", "versions": [{"status": "affected", "version": "0", "lessThan": "3.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2282x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.10.6", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2282x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.10.6", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch Q2300x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.10.7", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch PQ2300xb", "versions": [{"status": "affected", "version": "0", "lessThan": "2.10.7", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2542x", "versions": [{"status": "affected", "version": "0", "lessThan": "3.10.6", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2542x", "versions": [{"status": "affected", "version": "0", "lessThan": "3.10.6", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2542xh", "versions": [{"status": "affected", "version": "0", "lessThan": "3.10.6", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch PX2060", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G1280", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P1280", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P1281x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G1282", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P1282", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2121", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2121", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch PQ2121x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch Q2121x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2280x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2280x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch Q2200x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch PQ2200xb", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2100", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2100", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch G2540x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}, {"vendor": "DrayTek Corporation", "product": "VigorSwitch P2540x", "versions": [{"status": "affected", "version": "0", "lessThan": "2.9.10", "versionType": "custom"}], "defaultStatus": "unaffected"}]}], "published": "2026-08-24T18:17:18.890", "references": [{"url": "https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-buffer-overflow-via-poe-schedule-profile", "source": "disclosure@vulncheck.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-120"}]}], "descriptions": [{"lang": "en", "value": "Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the poe_schedule_profile function. The vulnerability is caused by repeated concatenation of the start_date, start_time, duration_time, how_often, weekdays, monthly_date, and cycle_duration fields into small fixed-size buffers without proper length checks. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device's web management interface."}], "lastModified": "2026-08-26T17:08:22.300", "sourceIdentifier": "disclosure@vulncheck.com"}