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Linux KernelOperating system · Linux

CVE-2026-53072

HIGH · 8.8 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 5.10.258 / 5.15.209 or later.
See remediation →
93/100
Remediation priority · Urgent
No privileges Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm() assumes it is held, and if conn is deleted concurrently -> UAF. Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen, and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred listening socket code paths, hci_connect_cfm(conn) is called with hdev->lock held. Fix by holding the lock.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Race condition and Use-After-Free vulnerability in Linux kernel Bluetooth subsystem where hci_conn_request_evt() calls hci_connect_cfm(conn) without holding hdev->lock when HCI_PROTO_DEFER is set. Normally hci_connect_cfm() expects the lock to be held, and concurrent connection deletion can lead to UAF. Only SCO and ISO protocols use HCI_PROTO_DEFER.

MitigationApply the kernel patch that ensures hdev->lock is acquired before calling hci_connect_cfm() in the deferred setup code path.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 3.17, < 5.10.258>= 5.11, < 5.15.209>= 5.16, < 6.1.175>= 6.2, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version for Bluetooth fix
    Run 'uname -r' to get your kernel version, then check if the hci_conn_request_evt function has the lock fix applied by reviewing kernel source or release notes
    Affected if The kernel version predates the patch that adds hdev->lock before hci_connect_cfm in the HCI_PROTO_DEFER code path
  2. Verify Bluetooth subsystem is loaded
    Run 'lsmod | grep bluetooth' or check 'rfkill list' to see if Bluetooth is available
    Affected if Bluetooth kernel modules are loaded and the Bluetooth subsystem is active
  3. Identify active SCO connections
    Run 'hcitool con' or check /sys/kernel/debug/bluetooth/hci*/*_connections for SCO link type connections
    Affected if SCO (Synchronous Connection-Oriented) Bluetooth connections are active
  4. Identify active ISO connections
    Check for Isochronous (ISO) channels via 'btmon' log or /sys/kernel/debug/bluetooth/hci*/*_connections for ISO link type
    Affected if ISO (Ischronous) Bluetooth connections are active
  5. Check for deferred setup listeners
    Inspect Bluetooth driver configuration or kernel debug logs for HCI_PROTO_DEFER flag usage in SCO/ISO setup
    Affected if SCO or ISO connections are using deferred setup (HCI_PROTO_DEFER) which triggers the vulnerable code path

You are affected if your kernel contains the vulnerable code path AND you have active SCO or ISO connections using deferred setup (HCI_PROTO_DEFER), which creates the race condition for the Use-After-Free.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 5.10.258 / 5.15.209 / 6.1.175 or later
Fixed in 5.10.2585.15.2096.1.175
Interim mitigation

Apply the kernel patch that ensures hdev->lock is acquired before calling hci_connect_cfm() in the deferred setup code path.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53072 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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