Monitor vulnerabilities like this one.
Sign up free to get alerted when software you use is affected.
7.4
Tenda AC21 Router Buffer Overflow via Malicious Input
CVE-2026-4565
Summary
A bug in the Tenda AC21 router's quality of service settings can be exploited by an attacker to remotely crash the device. This can be done by sending specially crafted data to the router. To protect your network, update your Tenda AC21 router to the latest firmware version as soon as possible.
Original title
A vulnerability was detected in Tenda AC21 16.03.08.16. Impacted is the function formSetQosBand of the file /goform/SetNetControlList. Performing a manipulation of the argument list results in buff...
Original description
A vulnerability was detected in Tenda AC21 16.03.08.16. Impacted is the function formSetQosBand of the file /goform/SetNetControlList. Performing a manipulation of the argument list results in buffer overflow. The attack can be initiated remotely. The exploit is now public and may be used.
nvd CVSS2.0
9.0
nvd CVSS3.1
8.8
nvd CVSS4.0
7.4
Vulnerability type
CWE-119
Buffer Overflow
CWE-120
Classic Buffer Overflow
Published: 23 Mar 2026 · Updated: 23 Mar 2026 · First seen: 23 Mar 2026