# CVE-2026-64175: wifi: iwlwifi: mld: stop TX during firmware restart

> A missing check in the iwlwifi driver causes a tight loop during firmware crashes, leading to CPU exhaustion and memory pressure under high network traffic.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64175, DEBIAN-CVE-2026-64175, GHSA-6wqh-xprc-m65r, UBUNTU-CVE-2026-64175

## What is CVE-2026-64175?

CVE-2026-64175 is a high-severity denial of service vulnerability in Linux kernel, published on 19 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

wifi: iwlwifi: mld: stop TX during firmware restart

When iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel
BE201/Wi-Fi 7), iwl_mld_nic_error() sets mld->fw_status.in_hw_restart
to true. However, iwl_mld_tx_from_txq() does not check this flag before
dequeuing frames from mac80211 and pushing them to the transport layer.

Since the firmware is dead, iwl_trans_tx() returns -EIO for each frame,
which then gets freed immediately. Under high-throughput conditions
(e.g., Tailscale UDP traffic or active SSH sessions), this creates a
tight dequeue-send-fail-free loop that wastes CPU cycles and generates
rapid skb allocation churn, leading to memory pressure from slab
fragmentation.

The RX path already has this guard (iwl_mld_rx_mpdu checks
in_hw_restart at rx.c:1906), and so does the TXQ allocation worker
(iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to
iwl_mld_tx_from_txq() to stop all TX during firmware restart.

Frames left in mac80211's TXQs are naturally drained after restart
completes, when queue reallocation triggers iwl_mld_tx_from_txq()
via iwl_mld_add_txq_list(), or when new upper-layer traffic invokes
wake_tx_queue.

Tested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on
kernel 6.19.5 where the firmware crashes approximately every 10-15
minutes under Tailscale traffic.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-64175?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64175?

Apply the vendor's patch.

## Is CVE-2026-64175 being exploited?

There is no known exploitation of CVE-2026-64175 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64175 and fix it if it is affected.

What it is: CVE-2026-64175 is a high-severity denial of service vulnerability in Linux kernel, published on 19 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-64175 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-64175/ (Markdown: https://insights.sbomify.com/CVE-2026-64175/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64175
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64175
- OSV: https://osv.dev/vulnerability/CVE-2026-64175

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64175/
Summaries are generated and may contain mistakes; the official description above is the record.