# CVE-2026-98186: wifi: mwifiex: bound the pairwise-cipher OUI walk to the IE length

> A crafted Wi-Fi beacon can cause an out-of-bounds read in the mwifiex driver, potentially leaking kernel memory or crashing the system.

- **Severity:** Not scored
- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106134, BELL-CVE-2026-98186, DEBIAN-CVE-2026-98186, GHSA-vmvq-5qrr-gvg2, UBUNTU-CVE-2026-98186

## What is CVE-2026-98186?

CVE-2026-98186 is a memory corruption vulnerability in Linux, published on 6 Oct 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: mwifiex: bound the pairwise-cipher OUI walk to the IE length

mwifiex_search_oui_in_ie() reads a pairwise-cipher (PTK) count from a
beacon/probe-response RSN or WPA information element and then walks that
many 4-byte OUIs, comparing each with memcmp(). The count comes straight
from the (attacker-supplied) IE and is never checked against the
element's own length, and the callers admit the element on element_id
alone (has_ieee_hdr() / has_vendor_hdr(), no length check). A crafted
RSN/WPA IE with a large pairwise count therefore makes the walk read up
to 255 * 4 bytes past the element -- an out-of-bounds read of the
kmemdup()'d beacon buffer, reachable from any AP whose beacon/probe
response is processed during scan-result parsing.

Pass the number of IE bytes available at the OUI list and bound the walk
to the element. Keep the length signed and reject a negative value
before any unsigned arithmetic, so a small or zero IE length cannot
underflow to a large size_t and defeat the bound.

Found by 0sec automated security-research tooling (https://0sec.ai).

## Which versions are affected by CVE-2026-98186?


## How do I fix CVE-2026-98186?

Apply the vendor's patch.

## Is CVE-2026-98186 being exploited?

There is no known exploitation of CVE-2026-98186 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98186 and fix it if it is affected.

What it is: CVE-2026-98186 is a memory corruption vulnerability in Linux, published on 6 Oct 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-2026-98186 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-2026-98186/ (Markdown: https://insights.sbomify.com/CVE-2026-98186/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98186
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98186
- OSV: https://osv.dev/vulnerability/CVE-2026-98186

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98186/
Summaries are generated and may contain mistakes; the official description above is the record.