# CVE-2026-89524: wifi: ath6kl: clamp assoc request/response lengths before subtracting IE offsets

> An integer underflow in the ath6kl WiFi driver allows attackers to disclose adjacent kernel memory to user space via crafted association events.

- **Severity:** High 8.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100587, BELL-CVE-2026-89524, DEBIAN-CVE-2026-89524, GHSA-5r7p-vjpr-vvgf, UBUNTU-CVE-2026-89524

## What is CVE-2026-89524?

CVE-2026-89524 is a high-severity vulnerability in Linux, published on 11 Sep 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: ath6kl: clamp assoc request/response lengths before subtracting IE offsets

ath6kl_cfg80211_connect_event() subtracts fixed IE offsets from
assoc_req_len (-= 4) and assoc_resp_len (-= 6), both u8, with no lower
bound. The aggregate check recently added to ath6kl_wmi_connect_event_rx()
bounds the declared lengths from above (their sum must fit the received
event), but an assoc request/response shorter than its fixed offset still
underflows here: the u8 wraps to ~250, and cfg80211_connect_result() /
cfg80211_roamed() then treat that wrapped value as the IE length and copy
that many bytes out of the small assoc_info buffer to user space via
nl80211, disclosing adjacent slab memory.

Clamp both lengths to their offsets before subtracting.

Found by 0sec (https://0sec.ai) using automated source analysis; the
missing lower bound is evident from source. Compile-tested.

## Which versions are affected by CVE-2026-89524?


## How do I fix CVE-2026-89524?

Apply the vendor's patch.

## Is CVE-2026-89524 being exploited?

There is no known exploitation of CVE-2026-89524 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89524 and fix it if it is affected.

What it is: CVE-2026-89524 is a high-severity vulnerability in Linux, published on 11 Sep 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-2026-89524 in the wild and no public exploit code.

Affected product: Linux. 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-2026-89524/ (Markdown: https://insights.sbomify.com/CVE-2026-89524/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89524
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89524
- OSV: https://osv.dev/vulnerability/CVE-2026-89524

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89524/
Summaries are generated and may contain mistakes; the official description above is the record.