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Vulnerability record · CVE-2026-71939 · published 24 August 2026

CVE-2026-71939: Classic buffer overflow vulnerability

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the acl_general_setup Add ACE function. The vulnerability is caused by copying the name field into a fixed-size buffer without length validation. 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.

8.6 CVSS 4.0 High EPSS 0.68% · top 49.4% CWE-120 · Classic buffer overflow Deferred
8.6CVSS 4.0 base score
0.68%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
26 Aug 2026Last modified by NVD

Description

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the acl_general_setup Add ACE function. The vulnerability is caused by copying the name field into a fixed-size buffer without length validation. 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: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:

References

LinkTags
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-acl-general-setup-add-ace

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Source: NIST National Vulnerability Database (record CVE-2026-71939), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.