# CVE-2026-98698: wifi: mac80211: handle empty FILS association request payload

> A remote attacker can cause a kernel crash or memory corruption by sending a crafted FILS association request with an empty payload to a Linux Wi-Fi interface.

- **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:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-108744, BELL-CVE-2026-98698, DEBIAN-CVE-2026-98698, GHSA-873v-4wm2-m9cr, UBUNTU-CVE-2026-98698

## What is CVE-2026-98698?

CVE-2026-98698 is a vulnerability in Linux, published on 18 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: mac80211: handle empty FILS association request payload

fils_encrypt_assoc_req() accepts a (Re)Association Request frame whose
last element is the FILS Session element.  crypt_len is then zero and
aes_siv_encrypt() is called with an empty plaintext.

kmemdup() returns ZERO_SIZE_PTR for a zero-length allocation, so the
unconditional sg_init_one() puts an invalid page into the scatterlist.
With CONFIG_DEBUG_SG this triggers a kernel BUG in sg_set_buf();
without the debug check the bogus page is handed to the crypto backend.

AES-SIV is defined for empty plaintext and the S2V result is then the
complete output, so handle this case before the CTR step, which has
nothing to encrypt.

## Which versions are affected by CVE-2026-98698?


## How do I fix CVE-2026-98698?

Apply the vendor's patch.

## Is CVE-2026-98698 being exploited?

There is no known exploitation of CVE-2026-98698 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98698 and fix it if it is affected.

What it is: CVE-2026-98698 is a vulnerability in Linux, published on 18 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-2026-98698 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-2026-98698/ (Markdown: https://insights.sbomify.com/CVE-2026-98698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98698
- OSV: https://osv.dev/vulnerability/CVE-2026-98698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98698/
Summaries are generated and may contain mistakes; the official description above is the record.