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

Q: Is CVE-2026-98189 being exploited?

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

Not scored Published 6 Oct 2026 Updated 19 Oct 2026

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.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

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.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-98189 being exploited?