Buffer overflow in Draytek Corporation Vigorswitch Fx2120
CVE-2026-71939
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.
Vulnerability class: Buffer Overflow
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Draytek Corporation Vigorswitch Fx2120
- Draytek Corporation Vigorswitch G1280
- Draytek Corporation Vigorswitch G1282
- Draytek Corporation Vigorswitch G2100
- Draytek Corporation Vigorswitch G2121
- Draytek Corporation Vigorswitch G2280x
- Draytek Corporation Vigorswitch G2282x
- Draytek Corporation Vigorswitch G2540x
- Draytek Corporation Vigorswitch G2540xs
- Draytek Corporation Vigorswitch G2542x
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-71939?
- CVE-2026-71939 is a high-severity vulnerability in Draytek Corporation Vigorswitch Fx2120, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.2/10. Published 2026-08-24.
- How severe is CVE-2026-71939?
- High severity. CVSS v3 base score is 7.2 out of 10.