# CVE-2026-98827: wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE

> A buffer overflow in the ath9k_htc WiFi driver allows remote attackers to cause memory corruption and potential code execution via crafted large frames.

- **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:** 19 Oct 2026
- **Also known as:** AZL-108746, BELL-CVE-2026-98827, DEBIAN-CVE-2026-98827, GHSA-x38j-g3ww-cf25, UBUNTU-CVE-2026-98827

## What is CVE-2026-98827?

CVE-2026-98827 is a memory corruption 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: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE

__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a
single tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch
by record count but never by cumulative byte length.

With large frames (MTU 2304), 20 aggregated frames of 2292 bytes
each exceed the allocation (20 * 2296 = 45920 bytes), so the
memcpy() in the loop writes up to 13152 bytes past tx_buf->buf
before usb_submit_urb().

Peek the queue head and stop before copying any record that would
cross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover
skbs remain queued and are drained on the next URB completion.

The byte bound changes the loop's exit semantics: it can now exit
before i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on
that last index (len += offset), so an early break would submit a
URB holding only the last record's length while every dequeued skb
is freed on completion, silently dropping frames. Make tx_buf->len
a running total and advance tx_buf->offset per record instead; the
stride round_up(nskb->len + 4, 4) is identical to the stock stride
when the loop runs to completion.

Tested on hardware with an MTU 2304 flood: the loop stops at
record 15 (len = 32144, offset = 32144, within 32768), no
oversized URB is submitted, and MTU 1500 pings pass 20/20.

## Which versions are affected by CVE-2026-98827?


## How do I fix CVE-2026-98827?

Apply the vendor's patch.

## Is CVE-2026-98827 being exploited?

There is no known exploitation of CVE-2026-98827 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98827 and fix it if it is affected.

What it is: CVE-2026-98827 is a memory corruption 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-2026-98827 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-2026-98827/ (Markdown: https://insights.sbomify.com/CVE-2026-98827/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98827
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98827
- OSV: https://osv.dev/vulnerability/CVE-2026-98827

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98827/
Summaries are generated and may contain mistakes; the official description above is the record.