# CVE-2026-64325: wifi: mt76: mt7921/mt7925: fix NULL dereference in CSA beacon

> A remote attacker can cause a kernel crash by sending a crafted CSA beacon during a station disconnect, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-64325, DEBIAN-CVE-2026-64325, GHSA-6c49-xc7v-mqvw, ROOT-OS-UBUNTU-2204-CVE-2026-64325, UBUNTU-CVE-2026-64325

## What is CVE-2026-64325?

CVE-2026-64325 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

wifi: mt76: mt7921/mt7925: fix NULL dereference in CSA beacon

This patch is based on a BUG as reported by Bongani Hlope at
https://lore.kernel.org/all/20260502125824.425d7159@bongani-mini.home.org.za/

When a channel-switch announcement (CSA) beacon is received,
cfg80211 queues a wiphy work item that eventually calls
mt7921_channel_switch_rx_beacon(). If the station disconnects
(or the channel context is otherwise torn down) between the
time the work is queued and the time it runs, the driver's
dev->new_ctx pointer can already have been cleared to NULL.
mt7921_channel_switch_rx_beacon() then dereferences new_ctx
unconditionally, triggering a NULL pointer dereference at
address 0x0:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  RIP: 0010:mt7921_channel_switch_rx_beacon+0x1f/0x100 [mt7921_common]

The same missing guard exists in mt7925_channel_switch_rx_beacon(),
which shares the same code pattern introduced by the same commit.

Add an early-return NULL check for dev->new_ctx in both
mt7921_channel_switch_rx_beacon() and
mt7925_channel_switch_rx_beacon(). When new_ctx is NULL there is
no pending channel switch to process, so returning immediately is
the correct and safe action.

Oops-Analysis: http://oops.fenrus.org/reports/lkml/20260502125824.425d7159@bongani-mini.home.org.za/report.html

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-64325?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64325?

Apply the vendor's patch.

## Is CVE-2026-64325 being exploited?

There is no known exploitation of CVE-2026-64325 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-2026-64325 and fix it if it is affected.

What it is: CVE-2026-64325 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-64325 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-2026-64325/ (Markdown: https://insights.sbomify.com/CVE-2026-64325/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64325
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64325
- OSV: https://osv.dev/vulnerability/CVE-2026-64325

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64325/
Summaries are generated and may contain mistakes; the official description above is the record.