CVE-2026-13351: Zephyrproject Zephyr

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Zephyrproject Zephyr: up to and including 4.4.1

Published 2026-06-25. Last modified 2026-07-06.