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Response snapshot Oct 27, 2026, 04:42 UTC

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VulnerabilityCVE-2026-98456

Linux kernel: Bluetooth: mgmt: fix race in read_unconf_index_list()

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.

At a glance

Exploited
Not known
Severity
7.0 High (CVSS 3.1)
Chance of exploitation
0.1% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-98456 (opens a new tab)

What happened

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[].

Continue reading

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.

Scores and how they were measured

CVSS base severity

7.0

Version 3.1As of

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.1%

Scored Percentile 2.3%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-98456 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-98456, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 24). Linux kernel: Bluetooth: mgmt: fix race in read_unconf_index_list() (CVE-2026-98456). https://kevwire.com/record/CVE-2026-98456

MLA

"Linux kernel: Bluetooth: mgmt: fix race in read_unconf_index_list() (CVE-2026-98456)." KEVWire, 24 Oct. 2026, kevwire.com/record/CVE-2026-98456.

Chicago

KEVWire. "Linux kernel: Bluetooth: mgmt: fix race in read_unconf_index_list() (CVE-2026-98456)." Last modified October 24, 2026. https://kevwire.com/record/CVE-2026-98456.

Evidence summary (plain text)

Linux kernel: Bluetooth: mgmt: fix race in read_unconf_index_list() (Oct 18, 2026).
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.
CVSS 7.0 (version 3.1; evidence as of Oct 24, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-98456).
EPSS 0.1% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-98456&date=2026-10-26).
Sources:
NVD CVE-2026-98456: https://nvd.nist.gov/vuln/detail/CVE-2026-98456
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?pubStartDate=2026-10-12T13:35:55.142Z&pubEndDate=2026-10-26T13:35:55.142Z&resultsPerPage=500&startIndex=4500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-98456&date=2026-10-26
Record ID: CVE-2026-98456.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

Record detail