---
id: CVE-2025-40301
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_event: validate skb length for unknown CC opcode

  In hci_cmd_complete_evt(), if the command complete event has an unknown
  opcode, we assume the first byt…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_event: validate skb length for unknown CC opcode

  In hci_cmd_complete_evt(), if the command complete event has an unknown
  opcode, we assume the first byt…
severity: high
cvss: 7.6
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
published: '2025-12-08'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:10:00.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40301'
references:
  - url: 'https://git.kernel.org/stable/c/1a0ddaaf97405dbd11d4cb5a961a3f82400e8a50'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5c5f1f64681cc889d9b13e4a61285e9e029d6ab5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/779f83a91d4f1bf5ddfeaf528420cbb6dbf03fa8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cf2c2acec1cf456c3d11c11a7589e886a0f963a9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fea895de78d3bb2f0c09db9f10b18f8121b15759'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00271
epssPercentile: 0.1797
ingestedAt: '2026-10-14T23:00:02.018Z'
---

## Overview

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

Bluetooth: hci_event: validate skb length for unknown CC opcode

In hci_cmd_complete_evt(), if the command complete event has an unknown
opcode, we assume the first byte of the remaining skb->data contains the
return status. However, parameter data has previously been pulled in
hci_event_func(), which may leave the skb empty. If so, using skb->data[0]
for the return status uses un-init memory.

The fix is to check skb->len before using skb->data.

## Remediation

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