CVE-2026-71935

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the webBackupAction function. The vulnerability is caused by repeated string concatenation of the pathN, valueN, key, and option fields into fixed-size stack buffers without total 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-webbackupaction

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-24 18:17

Updated : 2026-08-26 17:08

NVD link : CVE-2026-71935

Mitre link : CVE-2026-71935

CVE.ORG link : CVE-2026-71935

JSON object : View

Products Affected

No product.

CWE

CWE-120

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

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The vulnerability is caused by repeated string concatenation of the pathN, valueN, key, and option fields into fixed-size stack buffers without total 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"}