---
id: CVE-2026-63991
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

  The skb_clone() function can return NULL if memory allocation fails.
  send_mcast_pkt() calls skb_…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

  The skb_clone() function can return NULL if memory allocation fails.
  send_mcast_pkt() calls skb_…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.14, < 5.10.259'
  - 'linux_kernel >= 5.11, < 5.15.210'
  - 'linux_kernel >= 5.16, < 6.1.176'
  - 'linux_kernel >= 6.2, < 6.6.143'
  - 'linux_kernel >= 6.7, < 6.12.93'
  - 'linux_kernel >= 6.13, < 6.18.35'
  - 'linux_kernel >= 6.19, < 7.0.12'
  - linux_kernel = 7.1
patched:
  - linux_kernel 7.0.12
published: '2026-07-19'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T20:30:42.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63991'
references:
  - url: 'https://git.kernel.org/stable/c/2061d080a013c0ec0a56162cd501fb36d2befc26'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3c40d381ce04f9575a5d8b542898183c3b4b38dc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3d5d81d294ba09487c86bc4ba33dc4a4bec5d215'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9903a04becf059e44cccf625e23689b7d4378384'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9afcb5ea080af13aab37930da627db43bd277665'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b06203ac5f12929d79146bb9f063c2af1d679e63'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d630c4b25f36e0e68461561e4c70957ec37fdedd'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e673889a35a5e4c586d0fae67d8755ca4367d3e2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.0022
epssPercentile: 0.11346
ingestedAt: '2026-10-07T20:46:46.957Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

The skb_clone() function can return NULL if memory allocation fails.
send_mcast_pkt() calls skb_clone() without checking the return value, which
can lead to a NULL pointer dereference in send_pkt() when it dereferences
skb->data.
Add a NULL check after skb_clone() and skip the peer if the clone fails.

## Affected

- `linux_kernel >= 3.14, < 5.10.259`
- `linux_kernel >= 5.11, < 5.15.210`
- `linux_kernel >= 5.16, < 6.1.176`
- `linux_kernel >= 6.2, < 6.6.143`
- `linux_kernel >= 6.7, < 6.12.93`
- `linux_kernel >= 6.13, < 6.18.35`
- `linux_kernel >= 6.19, < 7.0.12`
- `linux_kernel = 7.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.12`