CVE-2026-4309 Missing authorization in Aterm GB1200PE

Medium 6.3 Published 27 Mar 2026 Updated 10 Apr 2026

Attackers can access device information and modify settings on NEC Aterm routers without proper authorization.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-4309?

CVE-2026-4309 is a medium-severity missing authorization vulnerability in NEC Platforms, Ltd. Aterm GB1200PE, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Missing Authorization vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to get a specific device information and change the settings via network.

Weakness: CWE-862

Which versions are affected by CVE-2026-4309?

It affects 20 products.

Products include Nec Aterm W1200ex-Ms Firmware, Nec Aterm Wf1200cr Firmware, Nec Aterm Wg1200cr Firmware, Nec Aterm Wg1200hp2 Firmware, Nec Aterm Wg1200hp3 Firmware, Nec Aterm Wg1200hp4 Firmware and 14 more.

How do I fix CVE-2026-4309?

No fix has been published for CVE-2026-4309 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-4309 being exploited?

There is no known exploitation of CVE-2026-4309 in the wild and no public exploit code.

Sources

Also known as GHSA-gqp3-283g-mgqc.