---
id: CVE-2026-63976
title: 'Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success

  l2cap_ecred_reconf_rsp() returns early on success without clearing
  chan->ident. Every other L2CAP …
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 >= 15f02b91056253e8cdc592888f431da0731337b8 <
    59f5ecf6ad5c4db6ae81965a96156954a3b0d89a
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    ae0152d77d101c920769934fb102b18de0c6f526
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    c2afd2613fda90107c5e2fe8e855627451749c78
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    cc2b4f749de09975bfa06e58bbbad2f6acd4c79c
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    3b5b5f423b4fd23404a393bda8adba3cd6f74ef1
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    f39049304ba655ffcbb92edbdf8c51a1f1210bed
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    8e7977afaef37c6bd2b2654f1bce6ab40d471147
  - >-
    Linux >= 15f02b91056253e8cdc592888f431da0731337b8 <
    00e1950716c6ed67d74777b2db286b0fa23b4be9
  - Linux 5.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:34:26.280157Z'
published: '2026-07-19'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:15.571Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63976'
references:
  - url: 'https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a'
  - url: 'https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526'
  - url: 'https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78'
  - url: 'https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c'
  - url: 'https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1'
  - url: 'https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed'
  - url: 'https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147'
  - url: 'https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9'
tags:
  - cve.org
epss: 0.00456
epssPercentile: 0.38102
ingestedAt: '2026-10-16T17:24:46.786Z'
---

## Overview

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

Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success

l2cap_ecred_reconf_rsp() returns early on success without clearing
chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp,
l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a
successful transaction to prevent the channel from matching subsequent
responses with the recycled ident value.

A remote attacker that completed a reconfiguration as the peer can
replay a failure response with the stale ident, causing the kernel to
match and destroy the already-established channel via
l2cap_chan_del(chan, ECONNRESET).

Clear chan->ident for all matching channels on success, and harden the
failure path by using l2cap_chan_hold_unless_zero() consistent with
other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).

## Affected

- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 59f5ecf6ad5c4db6ae81965a96156954a3b0d89a`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < ae0152d77d101c920769934fb102b18de0c6f526`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < c2afd2613fda90107c5e2fe8e855627451749c78`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < cc2b4f749de09975bfa06e58bbbad2f6acd4c79c`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 3b5b5f423b4fd23404a393bda8adba3cd6f74ef1`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < f39049304ba655ffcbb92edbdf8c51a1f1210bed`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 8e7977afaef37c6bd2b2654f1bce6ab40d471147`
- `Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 00e1950716c6ed67d74777b2db286b0fa23b4be9`
- `Linux 5.7`

## Remediation

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