CVE-2026-1637: Tenda AC21 Firmware

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

A vulnerability was identified in Tenda AC21 16.03.08.16. The affected element is the function fromAdvSetMacMtuWan of the file /goform/AdvSetMacMtuWan. The manipulation leads to stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit is publicly available and might be used.

Affected products

• Tenda AC21 Firmware: version 16.03.08.16 only

Published 2026-01-29. Last modified 2026-06-17.