What is CVE-2026-71931?

CVE-2026-71931 is a high-severity vulnerability in Draytek Corporation Vigorswitch Fx2120, classified under OS Command Injection. CVSS score: 7.2/10. Published 2026-08-24.

How severe is CVE-2026-71931?

High severity. CVSS v3 base score is 7.2 out of 10.

RCE in Draytek Corporation Vigorswitch Fx2120

CVE-2026-71931

Multiple DrayTek VigorSwitch models contain a command injection vulnerability in the tftp_upgrade function. The vulnerability is caused by insufficient filtering before the filename field is concatenated into a command. A remote attacker can trigger this vulnerability via crafted input to execute arbitrary commands with root privileges. Exploitation requires valid administrative credentials for the device's web management interface.

Vulnerability class: Command Injection (OS Command Injection)

Published 2026-08-24 · last modified 2026-08-27.

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: 0.018 (77.6th percentile), scored 2026-10-09.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.024 · newest: 0.018 · change: -0.006

Affected products

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch… (vendor-advisory)
www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-os-command-inj… (third-party-advisory)

Frequently asked questions

What is CVE-2026-71931?: CVE-2026-71931 is a high-severity vulnerability in Draytek Corporation Vigorswitch Fx2120, classified under OS Command Injection. CVSS score: 7.2/10. Published 2026-08-24.
How severe is CVE-2026-71931?: High severity. CVSS v3 base score is 7.2 out of 10.