CVE-2026-5042 Belkin F9K1122 Parameter formCrossBandSwitch stack-based overflow
Remote attackers can exploit a stack-based buffer overflow in the Belkin F9K1122 router to execute arbitrary code or escalate privileges.
- 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-2026-5042?
CVE-2026-5042 is a high-severity memory corruption vulnerability in Belkin F9K1122, published on 29 Mar 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 Belkin F9K1122 1.00.33. The affected element is the function formCrossBandSwitch of the file /goform/formCrossBandSwitch of the component Parameter Handler. The manipulation of the argument webpage results in stack-based buffer overflow. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-5042?
It affects 1 product.
Products include Belkin F9k1122 Firmware.
How do I fix CVE-2026-5042?
No fix has been published for CVE-2026-5042 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-2026-5042 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5042 exists.
Other vulnerabilities in Belkin F9K1122
- CVE-2026-5608 Belkin F9K1122 formWlanSetup stack-based overflow
- CVE-2026-5043 Belkin F9K1122 Parameter formSetPassword stack-based overflow
- CVE-2026-5044 Belkin F9K1122 Setting formSetSystemSettings stack-based overflow
- CVE-2026-4566 Belkin F9K1122 formWISP5G stack-based overflow
- CVE-2025-7084 Belkin F9K1122 webs formWpsStart stack-based overflow
Sources
Also known as GHSA-h7qj-64j4-6grw.