# CVE-2026-64174: wifi: cfg80211: advance loop vars in cfg80211_merge_profile()

> A malicious beacon can cause excessive CPU usage in the Linux kernel Wi-Fi subsystem, potentially 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:** 19 Jul 2026
- **Updated:** 19 Jul 2026
- **Also known as:** BELL-CVE-2026-64174, DEBIAN-CVE-2026-64174, GHSA-rrg8-qcw5-j3cm, UBUNTU-CVE-2026-64174

## What is CVE-2026-64174?

CVE-2026-64174 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 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: cfg80211: advance loop vars in cfg80211_merge_profile()

cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS
profile that has been split across multiple consecutive MBSSID elements.
Its while-loop calls

	cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem)

but never advances mbssid_elem or sub_elem inside the body.  Each
iteration therefore searches for a continuation that follows the same
fixed pair; the helper returns the same next_mbssid; and the same
next_sub bytes are memcpy()'d into merged_ie at a growing offset until
the buffer fills.

Advance both mbssid_elem and sub_elem to the just-consumed continuation
so the next call to cfg80211_get_profile_continuation() searches for a
further continuation beyond it (or returns NULL when none exists).

A specially-crafted malicious beacon can take advantage of this bug
to cause the kernel to spend an excessive amount of time in
cfg80211_merge_profile (up to as much as 2ms per beacon received),
which could theoretically be abused in some way.

## Which versions are affected by CVE-2026-64174?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64174?

Apply the vendor's patch.

## Is CVE-2026-64174 being exploited?

There is no known exploitation of CVE-2026-64174 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-2026-64174 and fix it if it is affected.

What it is: CVE-2026-64174 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 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-2026-64174 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-2026-64174/ (Markdown: https://insights.sbomify.com/CVE-2026-64174/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64174
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64174
- OSV: https://osv.dev/vulnerability/CVE-2026-64174

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64174/
Summaries are generated and may contain mistakes; the official description above is the record.