CVE-2026-64557
Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied.
INFO
Published Date :
July 29, 2026, 9:16 a.m.
Last Modified :
July 29, 2026, 9:16 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64557
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply kernel updates to resolve the use-after-free.
- Ensure channel configuration is consolidated.
- Manage socket lifetimes carefully.
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-2026-64557.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64557 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-2026-64557
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-2026-64557 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64557 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 29, 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': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': 'b39298044e5534612511a2ff5de03ba5f6e7a820', 'versionType': 'git'}, {'status': 'affected', 'version': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': '8c37e4338c801ebb8cee52436c01c41e009f6e87', 'versionType': 'git'}, {'status': 'affected', 'version': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': '84e718b6a814edc84159361f9f454a4e92ae91ae', 'versionType': 'git'}, {'status': 'affected', 'version': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': '36da806f7fbaee56ad9e81859deec203f9728700', 'versionType': 'git'}, {'status': 'affected', 'version': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': '733e76e74e406c1d1ddc7369420dd8a47f48bb8a', 'versionType': 'git'}, {'status': 'affected', 'version': '8ffb929098a56939ac71509302eeab5b207bf262', 'lessThan': '6fef032af0092ed5ccb767239a9ac1bc38c08a40', 'versionType': 'git'}], 'programFiles': ['include/net/bluetooth/l2cap.h', 'net/bluetooth/6lowpan.c', 'net/bluetooth/l2cap_core.c', 'net/bluetooth/l2cap_sock.c', 'net/bluetooth/smp.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.13'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.13', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc3', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/bluetooth/l2cap.h', 'net/bluetooth/6lowpan.c', 'net/bluetooth/l2cap_core.c', 'net/bluetooth/l2cap_sock.c', 'net/bluetooth/smp.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied. Added Reference https://git.kernel.org/stable/c/36da806f7fbaee56ad9e81859deec203f9728700 Added Reference https://git.kernel.org/stable/c/6fef032af0092ed5ccb767239a9ac1bc38c08a40 Added Reference https://git.kernel.org/stable/c/733e76e74e406c1d1ddc7369420dd8a47f48bb8a Added Reference https://git.kernel.org/stable/c/84e718b6a814edc84159361f9f454a4e92ae91ae Added Reference https://git.kernel.org/stable/c/8c37e4338c801ebb8cee52436c01c41e009f6e87 Added Reference https://git.kernel.org/stable/c/b39298044e5534612511a2ff5de03ba5f6e7a820