CVE-2026-63831: In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() befo

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HIGH 8.8WATCHLISTUPGRADE

CVE-2026-63831 is a high-severity flaw (CVSS 8.8) affecting linux kernel. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data. They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the c

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 84%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-07-19
Last modified	2026-10-22

Publisher (CNA): kernel.org · Vendor: linux

Am I affected?

Timeline

2026-07-19Published CVE record published
2026-10-22 19:24 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 3.16 and < 5.10.260 · >= 5.11 and < 5.15.211 · >= 5.16 and < 6.1.177 · >= 6.2 and < 6.6.144 · >= 6.7 and < 6.12.95 · >= 6.13 and < 6.18.38 · >= 6.19 and < 7.1.3

Fixed in: 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3

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.

Exact fixes by distribution

Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source

sudo dnf upgrade --advisory=FEDORA-2026-0602a84203

Ubuntu 22.04 · linux · FIXED · 5.15.0-198.208

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "5.15.0-198.208" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · linux · NO FIX YET

Ubuntu 24.04 · linux · FIXED · 6.8.0-147.147

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.8.0-147.147" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · linux-hwe-5.15 · FIXED · 5.15.0-198.208~20.04.1

sudo apt update && sudo apt install --only-upgrade linux-hwe-5.15 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux-hwe-5.15)" ge "5.15.0-198.208~20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · linux-hwe-6.8 · NO FIX YET

Debian 12 · linux · FIXED · 6.1.177-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.1.177-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · linux · FIXED · 6.12.95-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.12.95-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · kernel · FIXED · kernel-6.12.0-211.59.1.el10_2

sudo dnf upgrade --advisory=RHSA-2026:71233 rpm -q kernel

RHEL 8 · kernel-rt · FIXED · kernel-rt-4.18.0-553.167.1.rt7.508.el8_10

sudo dnf upgrade --advisory=RHSA-2026:71016 rpm -q kernel-rt

RHEL 8 · kernel · FIXED · kernel-4.18.0-553.167.1.el8_10

sudo dnf upgrade --advisory=RHSA-2026:71213 rpm -q kernel

RHEL 9 · kernel · FIXED · kernel-5.14.0-687.51.1.el9_8

sudo dnf upgrade --advisory=RHSA-2026:71232 rpm -q kernel

RHEL 6 · kernel · NOT AFFECTED

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.

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References

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