CVE-2026-4566 Belkin F9K1122 formWISP5G stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the Belkin F9K1122 router's WISP configuration interface, 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-2026-4566?
CVE-2026-4566 is a high-severity memory corruption vulnerability in Belkin F9K1122, published on 23 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw has been found in Belkin F9K1122 1.00.33. The affected element is the function formWISP5G of the file /goform/formWISP5G. Executing a manipulation of the argument webpage can lead to stack-based buffer overflow. The attack can be launched remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-4566?
It affects 1 product.
Products include Belkin F9k1122 Firmware.
How do I fix CVE-2026-4566?
No fix has been published for CVE-2026-4566 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-2026-4566 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4566 exists.
Other vulnerabilities in Belkin F9K1122
- CVE-2026-5608 Belkin F9K1122 formWlanSetup stack-based overflow
- CVE-2026-5042 Belkin F9K1122 Parameter formCrossBandSwitch stack-based overflow
- CVE-2026-5043 Belkin F9K1122 Parameter formSetPassword stack-based overflow
- CVE-2026-5044 Belkin F9K1122 Setting formSetSystemSettings stack-based overflow
- CVE-2025-7084 Belkin F9K1122 webs formWpsStart stack-based overflow
Sources
Also known as GHSA-9c76-c4x3-j7c2.