---
id: CVE-2026-74300
title: 'Bluetooth: hci: validate codec capability element length'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci: validate codec capability element length

  Read Local Codec Capabilities returns a sequence of capability elements.
  Each element starts with a one-byte l…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    fc97fc8cf7f53fd3619db63e09050d20a3a0c4b1
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    290b36f9d1eb9b2f72b40d826f26b4a182ab15f7
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    f2ad01f55e07f9531efcea736087e6b8658a3440
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    ec4d352747a62c1082f16c11a74b37d6eb85a5a3
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    4bc16db0f11918e07edf9fdcda4a30cf4c9df45c
  - >-
    Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 <
    c38fbcdc407925c7088f7e5f11c1fff73d2d35a2
  - Linux 5.16
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:52:45.932939Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:55:31.589Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74300'
references:
  - url: 'https://git.kernel.org/stable/c/fc97fc8cf7f53fd3619db63e09050d20a3a0c4b1'
  - url: 'https://git.kernel.org/stable/c/290b36f9d1eb9b2f72b40d826f26b4a182ab15f7'
  - url: 'https://git.kernel.org/stable/c/f2ad01f55e07f9531efcea736087e6b8658a3440'
  - url: 'https://git.kernel.org/stable/c/ec4d352747a62c1082f16c11a74b37d6eb85a5a3'
  - url: 'https://git.kernel.org/stable/c/4bc16db0f11918e07edf9fdcda4a30cf4c9df45c'
  - url: 'https://git.kernel.org/stable/c/c38fbcdc407925c7088f7e5f11c1fff73d2d35a2'
tags:
  - cve.org
epss: 0.00403
epssPercentile: 0.32955
ingestedAt: '2026-10-16T19:46:24.381Z'
---

## Overview

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

Bluetooth: hci: validate codec capability element length

Read Local Codec Capabilities returns a sequence of capability elements.
Each element starts with a one-byte length followed by that many payload
bytes.

hci_read_codec_capabilities() checks that the skb contains the length
byte, but then validates only caps->len against the remaining skb
length.  A malformed controller response with one remaining byte and
caps->len set to one passes that check even though the element needs two
bytes.  The parser then records a two-byte capability and copies one
byte beyond the advertised response payload into the codec list.

Validate the full element size, including the length byte, before adding
it to the accumulated capability length.  This preserves all well-formed
capability elements and drops only truncated controller responses.

## Affected

- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < fc97fc8cf7f53fd3619db63e09050d20a3a0c4b1`
- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < 290b36f9d1eb9b2f72b40d826f26b4a182ab15f7`
- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < f2ad01f55e07f9531efcea736087e6b8658a3440`
- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < ec4d352747a62c1082f16c11a74b37d6eb85a5a3`
- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < 4bc16db0f11918e07edf9fdcda4a30cf4c9df45c`
- `Linux >= 8961987f3f5fa2f2618e72304d013c8dd5e604a6 < c38fbcdc407925c7088f7e5f11c1fff73d2d35a2`
- `Linux 5.16`

## Remediation

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