Look up another CVE · open CVE-2026-52918 in the interactive tracker
CVE-2026-52918
Bluetooth: serialize accept_q access
Published 2026-06-24 (4 months ago) by the Linux kernel CNA. Subsystem include/net. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-52918 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixedDLA-4665-1 · 2026-07-03 · text | 6.1.176-1 | Update the kernel and reboot. DLA-4665-1 shipped the fix on 2026-07-03, in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
bt_sock_poll() walks the accept queue without synchronization, while child teardown can unlink the same socket and drop its last reference. The unsynchronized accept queue walk has existed since the initial Bluetooth import. Protect accept_q with a dedicated lock for queue updates and polling. Also rework bt_accept_dequeue() to take temporary child references under the queue lock before dropping it and locking the child socket.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
include/net/bluetooth/bluetooth.h
net/bluetooth/af_bluetooth.c
- What this is
- BLUETOOTH SUBSYSTEMMAINTAINERS section matched on include/net/bluetooth/ · linux-bluetooth@vger.kernel.org · Supported
- Kernel module
- bluetooth
Check it on the machine
grep -w CONFIG_BT /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w bluetoothPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_BT
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-06-24 (4 months ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.28%, higher than 19.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- include/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.12 | 5.10.259 | d9ce4de05df2 |
| 2.6.12 | 5.15.210 | 41c8c1c7923e |
| 2.6.12 | 6.1.176 | 4ec17782fd18 |
| 2.6.12 | 6.6.142 | be43e6b40431 |
| 2.6.12 | 6.12.92 | 85f8674cae82 |
| 2.6.12 | 6.18.34 | 8b4c412e001b |
| 2.6.12 | 7.0.11 | a218bf69eb51 |
| 2.6.12 | 7.1 | e83f5e24da74 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4671-1 | 2026-07-05 | bullseye 6.1.176-1~deb11u1 | tracker |
| DLA-4665-1 | 2026-07-03 | bookworm 6.1.176-1 | tracker |
| DLA-4664-1 | 2026-07-03 | bullseye 5.10.259-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:AAttack vector, adjacent network
- The vulnerable accept queue is in the Bluetooth socket stack and is reachable through nearby Bluetooth peers opening and tearing down L2CAP/RFCOMM-style connections to a listening Bluetooth service.
- AC:LAttack complexity, low
- The race can be exercised repeatedly by driving connection and disconnection activity while the listener polls/accepts, and no rare kernel configuration or condition outside the attacker’s reasonable influence is required.
- PR:NPrivileges required, none
- An adjacent Bluetooth peer can reach the incoming connection and teardown paths without local system privileges or prior authenticated application access in low-security/default Bluetooth service scenarios.
- UI:NUser interaction, none
- No victim user action is required once the Bluetooth service/socket is listening; the attacker can initiate the relevant Bluetooth protocol traffic.
- S:UScope, unchanged
- The bug affects kernel Bluetooth socket state within the same host security authority and does not cross a VM, IOMMU, or similar security boundary.
- C:HConfidentiality impact, high
- The bug is a use-after-free/unsynchronized traversal of freed socket objects; under the required conservative scoring rule, UAF exposure is treated as potentially enabling high-impact kernel information disclosure.
- I:HIntegrity impact, high
- The fixed code also pins children during dequeue to prevent references to freed objects, and UAF/refcount operations on reclaimed kernel memory are conservatively treated as potentially enabling memory corruption or control-flow compromise.
- A:HAvailability impact, high
- A failed race or invalid traversal can dereference freed or attacker-influenced kernel memory, producing a kernel oops/panic or repeated Bluetooth service/kernel disruption.