In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: reject invalid 320 MHz CSA bandwidth The HT/VHT channel… (CVE-2026-98702)

The Linux kernel's mac80211 component did not properly validate HT/VHT channel definitions when receiving CSA frames indicating a 320 MHz bandwidth on non-6 GHz links. Although a warning was issued for this unsupported bandwidth, the code continued and read an uninitialized vht_operation.chan_width field. This uninitialized read could cause a kernel panic if the kernel was configured with panic_on_warn. The fix involves rejecting invalid channel definitions early to avoid the uninitialized read and associated kernel panic, while preserving existing fallback behavior.

This vulnerability can cause a denial of service via a kernel panic triggered by a specially crafted CSA frame with an invalid 320 MHz bandwidth indication on non-6 GHz WiFi links. Systems with panic_on_warn enabled are susceptible to this crash, potentially disrupting network connectivity or system availability.

A fix is available that rejects invalid 320 MHz CSA bandwidth channel definitions before processing, preventing the uninitialized read and kernel panic. Users should apply the official Linux kernel updates that include this patch. Since no patch links or vendor advisories were provided, check the Linux kernel mailing lists or official repositories for the relevant fix. No additional mitigations are indicated.