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

Bluetooth: mgmt: fix race in read_unconf_index_list()

read_unconf_index_list() counts unconfigured controllers before allocating
its response, then checks the device flags again while filling it.

hci_dev_list_lock stabilizes list membership, but it does not serialize the
per-device flags. During asynchronous controller setup, the worker can set
HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller
omitted from the allocation count can then become eligible for the fill
pass, causing an out-of-bounds write to rp->index[].

Allocate space for every device on hci_dev_list. Since list membership
cannot change while hci_dev_list_lock is held, the response remains large
enough regardless of flag transitions. The reported count and response
length still include only eligible unconfigured controllers.
Published: 2026-10-18
Score: 7 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote code execution or denial of service via Bluetooth mgmt race condition
Action: Apply patch
AI Analysis

Impact

The vulnerability is a race condition in the Linux kernel’s Bluetooth management code. During asynchronous controller setup the count of unconfigured controllers is obtained, the buffer is allocated, and then the device flags are checked again while filling the response. Because the per‑device flag changes are not serialised by the lock, a controller can become eligible for the fill step after the allocation pass, causing an out‑of‑bounds write to the response array. Such memory corruption can lead to a kernel crash or arbitrary code execution, potentially compromising the entire system.

Affected Systems

All kernels of the Linux operating system that implement the Bluetooth mgmt interface are affected. No specific versions are listed in the advisory; the issue exists in any kernel that has the pre‑patch implementation of read_unconf_index_list. The vendor is Linux and the product is the Linux kernel.

Risk and Exploitability

The CVSS score is 7. The EPSS score is <1% and the vulnerability is not listed in CISA’s KEV catalog. The out‑of‑bounds write can lead to kernel memory corruption, potentially causing a crash or arbitrary code execution. The likely attack vector is via the Bluetooth mgmt interface, which may be reachable locally or remotely depending on system configuration. Attackers could trigger the race by initiating controller setup or by flooding mgmt requests while a controller is in an intermediate state.

Generated by OpenCVE AI on October 24, 2026 at 15:23 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the Linux kernel to a version that includes the patch for read_unconf_index_list
  • If a kernel update is not immediately possible, disable the Bluetooth subsystem or restrict access to the mgmt interface to trusted users only
  • Remove or unload the bluetooth module from unneeded systems to minimise attack surface

Generated by OpenCVE AI on October 24, 2026 at 15:23 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4850-1 linux-6.12 security update
History

Fri, 30 Oct 2026 12:45:00 +0000


Sat, 24 Oct 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Tue, 20 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-122
CWE-823

Tue, 20 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-787
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Sun, 18 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-122
CWE-823

Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: mgmt: fix race in read_unconf_index_list() read_unconf_index_list() counts unconfigured controllers before allocating its response, then checks the device flags again while filling it. hci_dev_list_lock stabilizes list membership, but it does not serialize the per-device flags. During asynchronous controller setup, the worker can set HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller omitted from the allocation count can then become eligible for the fill pass, causing an out-of-bounds write to rp->index[]. Allocate space for every device on hci_dev_list. Since list membership cannot change while hci_dev_list_lock is held, the response remains large enough regardless of flag transitions. The reported count and response length still include only eligible unconfigured controllers.
Title Bluetooth: mgmt: fix race in read_unconf_index_list()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-30T12:38:14.270Z

Reserved: 2026-09-25T10:25:14.350Z

Link: CVE-2026-98456

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:16:56.003

Modified: 2026-10-30T13:21:14.533

Link: CVE-2026-98456

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98456 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-24T15:30:14Z

Weaknesses