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CVE-2026-80692
Bluetooth: hci_sync: hold conn in hci_connect_acl/le_sync() callbacks
Published 2026-08-28 (2 months ago) by the Linux kernel CNA. Subsystem net/bluetooth. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-80692 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 | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| Debian 14forky | fixed | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
There is theoretical UAF if the conn is freed while the hci_sync task is running. Hold refcount to avoid that.
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.
net/bluetooth/hci_sync.c
- What this is
- BLUETOOTH SUBSYSTEMMAINTAINERS section matched on 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
- 2026-08-28 (2 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
- 0.38%, higher than 29.9% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- net/bluetooth
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.9 | 6.18.57 | a4de6fc95b2f |
| 6.9 | 7.1.8 | 9a77f296aff4 |
| 6.9 | 7.2 | 2f5d635ad590 |
| 6.6.51 | 0 | 0 |
| 6.8.9 | 0 | 0 |
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
- Bluetooth HCI outgoing ACL/LE connection setup (hci_connect_acl_sync/hci_connect_le_sync) is driven by adjacent radio peers supplying HCI events (connection complete/failures, command status) while hci_cmd_sync_work blocks on controller replies on phones and laptops.
- AC:LAttack complexity, low
- Race between hci_cmd_sync_work using a bare hci_conn pointer and hci_conn_del/hci_conn_failed/create_le_conn_complete teardown; attacker controls both sides by concurrently initiating L2CAP/MGMT connects and aborting or inducing remote HCI failure events until the window hits.
- PR:NPrivileges required, none
- Adjacent Bluetooth peers need no Linux credentials; freeing runs on unauthenticated HCI connection events, and local triggering works via unprivileged AF_BLUETOOTH L2CAP connect() without CAP_NET_ADMIN or special namespaces.
- UI:NUser interaction, none
- Background Bluetooth auto-reconnect, pairing flows, or listening socket-driven outgoing connects create BT_OPEN hci_conn objects without deliberate user action; attacker timing of connect/teardown does not require social engineering.
- S:UScope, unchanged
- Kernel heap UAF within the Bluetooth stack enables local privilege escalation in the same kernel domain but does not cross VM, IOMMU, or sandbox boundaries.
- C:HConfidentiality impact, high
- Freed struct hci_conn is dereferenced in hci_acl_create_conn_sync, hci_le_create_conn_sync, and create_le_conn_complete (e.g., conn->pkt_type, conn->dst, conn->le_conn_timeout), enabling slab reuse and arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- Post-free writes occur to conn fields (state, flags, timers) and function-pointer members (cleanup, connect_cfm_cb), providing groomable heap corruption suitable for arbitrary kernel write and code execution.
- A:HAvailability impact, high
- UAF during hci_cmd_sync_work on connection setup reliably causes kernel oops/panic and can be retriggered by repeated connect/abort cycles from adjacent or local attackers.