---
id: CVE-2026-13351
title: >-
  net: Maliciously fragmented IPv6 packets can prevent receiving/processing
  future incoming packets
summary: >-
  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…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-772
vendor: zephyrproject-rtos
product: Zephyr
affected:
  - Zephyr < 3.7.2
  - Zephyr >= 4.0.0 < 4.2.2
  - Zephyr >= 4.3.0 < 4.3.1
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-25T18:00:39.412711Z'
published: '2026-06-25'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:10:20.993Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-13351'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-cv4q-2j56-4wqf
tags:
  - cve.org
epss: 0.00486
epssPercentile: 0.40335
ingestedAt: '2026-10-15T22:48:25.574Z'
---

## Overview

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

- `Zephyr < 3.7.2`
- `Zephyr >= 4.0.0 < 4.2.2`
- `Zephyr >= 4.3.0 < 4.3.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.