CVE-2021-31755: Tenda AC11 Router Stack Buffer Overflow Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 86.5% chance of exploitation in the next 30 days.

An issue was discovered on Tenda AC11 devices with firmware through 02.03.01.104_CN. A stack buffer overflow vulnerability in /goform/setmac allows attackers to execute arbitrary code on the system via a crafted post request.

Affected products

• Tenda AC11 Firmware: up to and including 02.03.01.104_cn

Published 2021-05-07. Last modified 2026-06-17.