CVE-2026-4565 Tenda AC21 SetNetControlList formSetQosBand buffer overflow
Remote attackers can trigger a buffer overflow in the Tenda AC21 router's QoS settings, potentially leading to code execution or service disruption.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-4565?
CVE-2026-4565 is a high-severity memory corruption vulnerability in Tenda AC21, published on 23 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-4565?
It affects 1 product.
Products include Tenda Ac21 Firmware.
How do I fix CVE-2026-4565?
No fix has been published for CVE-2026-4565 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-4565 being exploited?
There is no known exploitation of CVE-2026-4565 in the wild and no public exploit code.
Other vulnerabilities in Tenda AC21
- CVE-2025-9605 Tenda AC21/AC23 GetParentControlInfo stack-based overflow
- CVE-2023-24333 Command injection in n/a
- CVE-2026-1637 Tenda AC21 AdvSetMacMtuWan fromAdvSetMacMtuWan stack-based overflow
- CVE-2025-13445 Tenda AC21 SetIpMacBind stack-based overflow
- CVE-2025-13446 Tenda AC21 SetSysTimeCfg stack-based overflow
Sources
Also known as GHSA-mcx9-w62j-hjwr.