CVE-2026-90344 wifi: mac80211: disconnect on CSA to channel 0
A logic error in Linux kernel Wi-Fi handling fails to disconnect on invalid channel switches, potentially causing firmware crashes and denial of service.
- 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-2026-90344?
CVE-2026-90344 is a denial of service vulnerability in Linux, published on 17 Sep 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: disconnect on CSA to channel 0
The refactor for the CSA parsing erroneously equates channel zero and no information present, leading it to ignore a CSA on an AP that advertises a switch to that (invalid) channel. This leads to not disconnecting, which we should. For Intel devices, this can lead to a firmware crash.
Fix this by using an int type for the channel number as well as the opclass, and using a (negative) value that cannot be encoded in the element to indicate it's not present.
Which versions are affected by CVE-2026-90344?
How do I fix CVE-2026-90344?
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-2026-90344 being exploited?
There is no known exploitation of CVE-2026-90344 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90344, DEBIAN-CVE-2026-90344, GHSA-gpwq-pm3v-5v85, UBUNTU-CVE-2026-90344.