CVE-2026-74533
Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero hci_conn::iso_data is accessed and modified without lock or RCU. This leads to a race [Task hdev->workqueue] [Task 2] iso_recv iso_conn_put(conn) conn = LOAD hcon->iso_data iso_conn_free(conn) iso_conn_hold_unless_zero(conn) hcon->iso_data = NULL kfree(conn) kref_get_unless_zero(&conn->ref) /* UAF */ and also to races in iso_conn_add() vs. iso_conn_free(). Fix by adding spinlock hci_conn::proto_lock and using it to guard hci_conn::iso_data.
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-2026-74533
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 include the fix.
- Apply the provided patch for Bluetooth ISO handling.
- Add spinlock hci_conn::proto_lock.
- Guard hci_conn::iso_data access with the new lock.
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-2026-74533.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/876a3e94c70d0859d1dad1c986112d4f0d99eba8 | |
| https://git.kernel.org/stable/c/af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74533 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-2026-74533
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-2026-74533 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74533 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': '876a3e94c70d0859d1dad1c986112d4f0d99eba8', 'versionType': 'git'}, {'status': 'affected', 'version': 'dc26097bdb864a0d5955b9a25e43376ffc1af99b', 'lessThan': 'af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c', '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': ['include/net/bluetooth/hci_core.h', 'net/bluetooth/hci_conn.c', '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': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/bluetooth/hci_core.h', 'net/bluetooth/hci_conn.c', 'net/bluetooth/iso.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero hci_conn::iso_data is accessed and modified without lock or RCU. This leads to a race [Task hdev->workqueue] [Task 2] iso_recv iso_conn_put(conn) conn = LOAD hcon->iso_data iso_conn_free(conn) iso_conn_hold_unless_zero(conn) hcon->iso_data = NULL kfree(conn) kref_get_unless_zero(&conn->ref) /* UAF */ and also to races in iso_conn_add() vs. iso_conn_free(). Fix by adding spinlock hci_conn::proto_lock and using it to guard hci_conn::iso_data. Added Reference https://git.kernel.org/stable/c/876a3e94c70d0859d1dad1c986112d4f0d99eba8 Added Reference https://git.kernel.org/stable/c/af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c