CVE-2026-13351: Zephyr's IPv6 network stack can be prevented from receiving or processing future incoming packets by sending a

Q: How do I fix CVE-2026-13351?

zephyr: upgrade to newer than 4.4.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-13351 being exploited?

CVE-2026-13351 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-13351 affect?

CVE-2026-13351 affects zephyr. Severity is high (CVSS 7.5). 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 as

Q: How urgent is CVE-2026-13351?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-13351 is a high-severity flaw (CVSS 7.5) affecting zephyr. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 buf

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-772
Published	2026-06-25
Last modified	2026-10-25

Publisher (CNA): Zephyr Project · Vendor: zephyrproject

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-25 17:16 UTCPublished CVE record published
2026-10-25 22:10 UTCUpdated Record last modified

zephyrproject zephyr UPGRADE

Affected: <= 4.4.1

Fixed in: newer than 4.4.1

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-13351?

zephyr: upgrade to newer than 4.4.1. Exact commands for each OS are on this page.

Is CVE-2026-13351 being exploited?

CVE-2026-13351 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-13351 affect?

CVE-2026-13351 affects zephyr. Severity is high (CVSS 7.5). 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 as

How urgent is CVE-2026-13351?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-8023 HIGH 7.5 UPGRADE Zephyr's HTTP server (subsys/net/lib/http) provides a static-filesystem resource type (HTTP_RESOURCE_TYPE_STAT
CVE-2026-10655 MEDIUM 6.5 UPGRADE The asynchronous SNTP client in Zephyr (subsys/net/lib/sntp/sntp.c, sntp_close_async) closed the UDP socket fi
CVE-2026-7656 HIGH 8.1 UPGRADE The IPv6 Neighbor Discovery handlers in subsys/net/ip/ipv6_nbr.c (handle_ra_input, handle_ns_input, handle_na_
CVE-2026-10652 MEDIUM 4.8 UPGRADE Zephyr's DNS resolver (subsys/net/lib/dns) parses resource records from DNS responses in dns_unpack_answer(),
CVE-2026-10653 MEDIUM 6.4 UPGRADE The Zephyr net_buf library (lib/net_buf/buf.c) manipulated both of its reference counts -- the per-header buf-

References

← Back to latest CVEs