CVE-2026-98707 wifi: mac80211: shut down RX BA session timer on teardown
A use-after-free in the Linux kernel WiFi driver allows attackers to execute code or cause denial of service via crafted WiFi 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-2026-98707?
CVE-2026-98707 is an use after free 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: shut down RX BA session timer on teardown
Tearing down an RX BA session can leave the session timer queued on a freed tid_rx. Later timer-wheel processing and the timer callback itself then run against freed memory.
An RX BAR handler can dereference tid_rx under RCU before teardown unpublishes it and stay in its read-side critical section while teardown deletes the session timer. The stale handler can then rearm the timer after timer_delete_sync() returns and before the RCU callback frees tid_rx.
Use timer_shutdown_sync() so rearm attempts become ineffective once teardown starts. Keep reorder_timer unchanged: teardown marks the session removed under reorder_lock and its release path checks that state before rearming. session_timer has no equivalent guard because ieee80211_rx_h_ctrl() rearms it before taking reorder_lock.
Which versions are affected by CVE-2026-98707?
How do I fix CVE-2026-98707?
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-2026-98707 being exploited?
There is no known exploitation of CVE-2026-98707 in the wild and no public exploit code.
Sources
Also known as AZL-108690, BELL-CVE-2026-98707, DEBIAN-CVE-2026-98707, GHSA-8mvq-3rmc-c8vm, UBUNTU-CVE-2026-98707.