# CVE-2026-98189: wifi: wilc1000: fix RX buffer OOB-write in wilc_wlan_handle_isr_ext()

> A malicious SDIO device can trigger an out-of-bounds write in the wilc1000 WiFi driver, potentially leading to kernel memory corruption or system crashes.

- **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-106122, BELL-CVE-2026-98189, DEBIAN-CVE-2026-98189, GHSA-75q8-f2q5-cqqg, UBUNTU-CVE-2026-98189

## What is CVE-2026-98189?

CVE-2026-98189 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: wilc1000: fix RX buffer OOB-write in wilc_wlan_handle_isr_ext()

wilc_wlan_handle_isr_ext() takes the RX transfer size from the
device-reported interrupt status register (a 15-bit field shifted left by 2,
up to 131068 bytes) and reads that many bytes from the device into
rx_buffer, which is only WILC_RX_BUFF_SIZE (96K) large. The wrap
check only handles the current offset; the size itself is never
compared against the buffer, so a bogus SDIO device can make the driver
OOB-write rx_buffer by up to ~32K with data it controls.

The oversized transfer also leaves rx_buffer_offset past the end of
the buffer, after which the unsigned wrap check stops working and
the overflow can repeat.

Drop any transfer whose size exceeds the RX buffer, acknowledging
the data interrupt and re-arming the RX engine so the bogus frame is
discarded and reception can continue. This also restores the
rx_buffer_offset <= WILC_RX_BUFF_SIZE invariant the wrap check
relies on.

This is not expected to change driver behavior in most cases:
without this check, an oversized transfer would most likely
corrupt neighboring kernel memory instead of completing anyway, and
the drop path performs the same interrupt acknowledgment and RX
engine re-arming as the normal path, so subsequent transfers are
received unaffected.

Discovered by Atuin - Automated Vulnerability Discovery Engine.

## Which versions are affected by CVE-2026-98189?


## How do I fix CVE-2026-98189?

Apply the vendor's patch.

## Is CVE-2026-98189 being exploited?

There is no known exploitation of CVE-2026-98189 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98189 and fix it if it is affected.

What it is: CVE-2026-98189 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-2026-98189 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-2026-98189/ (Markdown: https://insights.sbomify.com/CVE-2026-98189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98189
- OSV: https://osv.dev/vulnerability/CVE-2026-98189

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98189/
Summaries are generated and may contain mistakes; the official description above is the record.