CVE-2026-3978 D-Link DIR-513 formEasySetupWizard3 stack-based overflow

High 8.7 Published 12 Mar 2026 Updated 12 Mar 2026

Remote attackers can trigger a stack-based buffer overflow in the D-Link DIR-513 router via the formEasySetupWizard3 interface, potentially leading to 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-2026-3978?

CVE-2026-3978 is a high-severity memory corruption vulnerability in D-Link DIR-513, published on 12 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability was detected in D-Link DIR-513 1.10. The impacted element is an unknown function of the file /goform/formEasySetupWizard3. The manipulation of the argument wan_connected results in stack-based buffer overflow. The attack can be launched remotely. The exploit is now public and may be used.

Weakness: CWE-121, CWE-119

Which versions are affected by CVE-2026-3978?

It affects 1 product.

Products include Dlink Dir-513 Firmware.

How do I fix CVE-2026-3978?

No fix has been published for CVE-2026-3978 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-2026-3978 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3978 exists.

Sources

Also known as GHSA-ccfc-w7hx-qcqw.