CVE-2026-2873 Tenda A21 openSchedWifi setSchedWifi stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the Tenda A21 router's scheduling function, potentially leading to arbitrary code execution.
- 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-2026-2873?
CVE-2026-2873 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 vulnerability was detected in Tenda A21 1.0.0.0. This issue affects the function setSchedWifi of the file /goform/openSchedWifi. Performing a manipulation of the argument schedStartTime/schedEndTime results in stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit is now public and may be used.
Which versions are affected by CVE-2026-2873?
It affects 1 product.
Products include Tenda A21 Firmware.
How do I fix CVE-2026-2873?
No fix has been published for CVE-2026-2873 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-2026-2873 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2873 exists.
Other vulnerabilities in Tenda A21
- CVE-2026-2870 Tenda A21 formSetQosBand set_qosMib_list stack-based overflow
- 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-2026-2874 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-6238-4w9x-vrrr.