CVE-2026-0640 Tenda AC23 PowerSaveSet sscanf buffer overflow

High 8.7 Published 6 Jan 2026 Updated 23 Feb 2026

Remote attackers can trigger a buffer overflow in the Tenda AC23 router via the PowerSaveSet 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-2026-0640?

CVE-2026-0640 is a high-severity memory corruption vulnerability in Tenda AC23, published on 6 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A weakness has been identified in Tenda AC23 16.03.07.52. This affects the function sscanf of the file /goform/PowerSaveSet. Executing a manipulation of the argument Time can lead to buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks.

Weakness: CWE-120, CWE-119

Which versions are affected by CVE-2026-0640?

It affects 1 product.

Products include Tenda Ac23 Firmware.

How do I fix CVE-2026-0640?

No fix has been published for CVE-2026-0640 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-2026-0640 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0640 exists.

Sources

Also known as GHSA-873q-r7q9-7r4r.