CVE-2026-90356 wifi: mt76: mt7996: free vif links after clearing wcid entries on full reset
A use-after-free vulnerability in the Linux kernel mt7996 WiFi driver allows attackers to cause denial of service or execute code via crafted wireless frames.
- 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-2026-90356?
CVE-2026-90356 is an use after free 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: free vif links after clearing wcid entries on full reset
mt7996_mac_reset_vif_iter() queues non-default vif links for kfree_rcu while dev->wcid[] still holds pointers to the wcid embedded in each freed link; mt76_reset_device() then dereferences those entries and runs mt76_wcid_cleanup() on them. If a grace period elapses in between, the cleanup operates on freed memory.
Run mt76_reset_device() first, so the wcid entries are cleaned up and cleared while the links are still valid.
Which versions are affected by CVE-2026-90356?
How do I fix CVE-2026-90356?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90356 being exploited?
There is no known exploitation of CVE-2026-90356 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90356, DEBIAN-CVE-2026-90356, GHSA-c2cq-r8gq-mfvq, UBUNTU-CVE-2026-90356.