CVE-2026-98702 wifi: mac80211: reject invalid 320 MHz CSA bandwidth
A remote attacker can crash the Linux kernel by sending a crafted Wi-Fi CSA frame if panic_on_warn is enabled.
- 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-2026-98702?
CVE-2026-98702 is a denial of service 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: reject invalid 320 MHz CSA bandwidth
The HT/VHT channel definition validator can receive a 320 MHz bandwidth indication from a received CSA frame on a non-6 GHz link. It warns for this unsupported width but continues with an uninitialized vht_operation.chan_width, which is then read by ieee80211_chandef_vht_oper(). With panic_on_warn enabled, this lets a received frame panic the kernel.
Reject the channel definition before entering the VHT operation conversion. This preserves the existing CSA fallback while avoiding both the warning and the uninitialized read.
Which versions are affected by CVE-2026-98702?
How do I fix CVE-2026-98702?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98702 being exploited?
There is no known exploitation of CVE-2026-98702 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98702, DEBIAN-CVE-2026-98702, GHSA-6466-2f74-2mgw, UBUNTU-CVE-2026-98702.