CVE-2026-63976
Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success
Description
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).
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 30, 2026, 2:51 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Apply specific patches for Bluetooth L2CAP.
- Clear chan->ident on success in L2CAP handlers.
- Use l2cap_chan_hold_unless_zero() in failure paths.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63976.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63976 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63976
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63976 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63976 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '59f5ecf6ad5c4db6ae81965a96156954a3b0d89a', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'ae0152d77d101c920769934fb102b18de0c6f526', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'c2afd2613fda90107c5e2fe8e855627451749c78', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'cc2b4f749de09975bfa06e58bbbad2f6acd4c79c', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '3b5b5f423b4fd23404a393bda8adba3cd6f74ef1', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'f39049304ba655ffcbb92edbdf8c51a1f1210bed', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '8e7977afaef37c6bd2b2654f1bce6ab40d471147', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '00e1950716c6ed67d74777b2db286b0fa23b4be9', 'versionType': 'git'}], 'programFiles': ['net/bluetooth/l2cap_core.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/bluetooth/l2cap_core.c'], 'defaultStatus': 'affected'}] Added Description 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). Added Reference https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9 Added Reference https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1 Added Reference https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a Added Reference https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147 Added Reference https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526 Added Reference https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78 Added Reference https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c Added Reference https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed