CVE-2026-90355 wifi: mt76: mt7996: clear stale link state on full reset
A flaw in the mt7996 Wi-Fi driver causes device inoperability and resource exhaustion after a full chip reset, requiring a kernel patch.
- 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-2026-90355?
CVE-2026-90355 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: mt76: mt7996: clear stale link state on full reset
After a full chip reset, mac80211 reconfig replays interface, link and channel context setup. mt7996_vif_link_add() short-circuits when the link_id is still marked in mvif->valid_links, a state introduced for postponing link teardown to interface removal. The reset path frees the link structures without clearing those bits, so the replayed setup never re-creates dev_info/bss_info/STA records in the restarted firmware and never re-registers the link wcid, leaving the device inoperative.
The reset path also leaks every allocated MLD index: per-link indices and the per-vif group/remap indices are re-allocated from scratch during reconfig, but the old bits stay set in the masks, so repeated full resets exhaust the index space.
Clear valid_links in the reset vif iterator and reset the MLD index masks alongside the existing omac_mask clearing.
Which versions are affected by CVE-2026-90355?
How do I fix CVE-2026-90355?
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-2026-90355 being exploited?
There is no known exploitation of CVE-2026-90355 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90355, DEBIAN-CVE-2026-90355, GHSA-5jf9-g6v9-f6vh, UBUNTU-CVE-2026-90355.