CVE-2026-74534
Bluetooth: ISO: fix refcounting of iso_conn
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix refcounting of iso_conn iso_conn_del() and iso_chan_del() have a race that results to double-put of iso_conn: [Task hdev->workqueue] [Task 2] iso_conn_del iso_chan_del iso_conn_hold_unless_zero iso_conn_lock iso_conn_lock conn->sk = NULL iso_conn_unlock sk = iso_sock_hold(conn) <---------´ if (!sk) iso_conn_put iso_conn_put iso_conn_put /* UAF */ The extra put for !sk in iso_conn_del() is currently required since failing iso_chan_add() may leave iso_conn not associated with any sk. Fix by having iso_pi(sk)->conn own refcount when non-NULL, so iso_conn_del does not need to put it. Adjust the iso_conn_add() refcounting so that conn is put if it does not get associated with an sk.
INFO
Published Date :
Aug. 15, 2026, 1:17 p.m.
Last Modified :
Aug. 15, 2026, 1:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74534
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
- Update the Linux kernel to incorporate the fix for the Bluetooth ISO refcounting issue.
- Ensure iso_conn_add refcounting is adjusted to handle non-associated sockets.
- Verify that iso_conn_del no longer requires an extra put when a socket is not associated.
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-2026-74534.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74534 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-2026-74534
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-2026-74534 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74534 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.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 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': 'dc26097bdb864a0d5955b9a25e43376ffc1af99b', 'lessThan': '3b921533e8aa95b77aadcf31737595578e735f3c', 'versionType': 'git'}, {'status': 'affected', 'version': 'dc26097bdb864a0d5955b9a25e43376ffc1af99b', 'lessThan': '8208b4939afb0a1977fffe902c3ca42fe0f3baaa', 'versionType': 'git'}, {'status': 'affected', 'version': 'dc26097bdb864a0d5955b9a25e43376ffc1af99b', 'lessThan': 'fdfde532ab1caa165fcd8985001157ac8b4db365', 'versionType': 'git'}, {'status': 'affected', 'version': 'f53e7489273dc2bb307bf50f319b3762d45534f0', 'versionType': 'git'}, {'status': 'affected', 'version': 'a58d0f5dac322e16cc75334d000666512341bde5', 'versionType': 'git'}, {'status': 'affected', 'version': '6.11.11', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.12.2', 'lessThan': '6.13', 'versionType': 'semver'}], 'programFiles': ['net/bluetooth/iso.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.13'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.13', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/bluetooth/iso.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix refcounting of iso_conn iso_conn_del() and iso_chan_del() have a race that results to double-put of iso_conn: [Task hdev->workqueue] [Task 2] iso_conn_del iso_chan_del iso_conn_hold_unless_zero iso_conn_lock iso_conn_lock conn->sk = NULL iso_conn_unlock sk = iso_sock_hold(conn) <---------´ if (!sk) iso_conn_put iso_conn_put iso_conn_put /* UAF */ The extra put for !sk in iso_conn_del() is currently required since failing iso_chan_add() may leave iso_conn not associated with any sk. Fix by having iso_pi(sk)->conn own refcount when non-NULL, so iso_conn_del does not need to put it. Adjust the iso_conn_add() refcounting so that conn is put if it does not get associated with an sk. Added Reference https://git.kernel.org/stable/c/3b921533e8aa95b77aadcf31737595578e735f3c Added Reference https://git.kernel.org/stable/c/8208b4939afb0a1977fffe902c3ca42fe0f3baaa Added Reference https://git.kernel.org/stable/c/fdfde532ab1caa165fcd8985001157ac8b4db365