Buffer overflow in Draytek Corporation Vigorswitch Fx2120
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.
Vulnerability class: Buffer Overflow
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (51.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.002
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
- www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch… (vendor-advisory)
- www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-buffer-overflo… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-71937?
- CVE-2026-71937 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-2026-71937?
- High severity. CVSS v3 base score is 7.2 out of 10.