CVE-2026-13351 net: Maliciously fragmented IPv6 packets can prevent receiving/processing future incoming packets

High 7.5 Published 25 Jun 2026 Updated 15 Oct 2026

Attackers can cause denial of service in Zephyr RTOS by sending malicious fragmented IPv6 packets that exhaust network buffers.

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-2026-13351?

CVE-2026-13351 is a high-severity denial of service vulnerability in Zephyrproject Zephyr, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Zephyr's IPv6 network stack can be prevented from receiving or processing future incoming packets by sending a small number of maliciously fragmented IPv6 packets. When such a packet is handled by the fragment-header processing path, the associated RX network packet buffer (allocated from a memory slab) is not released back to the pool. Repeating the malicious packet exhausts all RX buffer slots, after which the device can no longer obtain RX buffers and stops receiving traffic, resulting in a denial of service.

Weakness: CWE-772

Which versions are affected by CVE-2026-13351?

It affects 1 product.

Products include Zephyrproject Zephyr.

How do I fix CVE-2026-13351?

No fix has been published for CVE-2026-13351 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-13351 being exploited?

There is no known exploitation of CVE-2026-13351 in the wild and no public exploit code.

All Zephyrproject Zephyr vulnerabilities

Sources

Also known as GHSA-cv4q-2j56-4wqf.