CVE-2026-2870 Tenda A21 formSetQosBand set_qosMib_list stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the Tenda A21 router's QoS configuration interface, 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-2026-2870?
CVE-2026-2870 is a high-severity memory corruption vulnerability in Tenda A21, published on 21 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A security flaw has been discovered in Tenda A21 1.0.0.0. Affected by this issue is the function set_qosMib_list of the file /goform/formSetQosBand. The manipulation of the argument list results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.
Which versions are affected by CVE-2026-2870?
It affects 1 product.
Products include Tenda A21 Firmware.
How do I fix CVE-2026-2870?
No fix has been published for CVE-2026-2870 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-2026-2870 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2870 exists.
Other vulnerabilities in Tenda A21
- CVE-2026-2871 Tenda A21 SetIpMacBind fromSetIpMacBind stack-based overflow
- CVE-2026-2872 Tenda A21 MAC Filtering Configuration Endpoint setBlackRule set_device_name stack-based overflow
- CVE-2026-2873 Tenda A21 openSchedWifi setSchedWifi stack-based overflow
- CVE-2026-2874 Tenda A21 fast_setting_wifi_set form_fast_setting_wifi_set stack-based overflow
- CVE-2026-2886 Tenda A21 SetOnlineDevName set_device_name stack-based overflow
Sources
Also known as GHSA-wpqj-9q8f-r6hc.