CVE-2026-98699 wifi: mac80211: fix mesh fast xmit path deletion UAF
A use-after-free in the Linux kernel's mac80211 mesh networking allows attackers to cause denial of service or execute arbitrary code.
- 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-2026-98699?
CVE-2026-98699 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: fix mesh fast xmit path deletion UAF
mesh_fast_tx_cache() stores raw mesh_path pointers. Path deletion flushes the cache and then frees the path with kfree_rcu(), but a lookup that already holds the path can insert a new cache entry after the flush. The cache then points at freed memory.
Set MESH_PATH_DELETED before flushing, and skip inserting a cache entry if the path or MPP path is already deleted. Check this under the cache walk lock so it is ordered with the flush. Use WRITE_ONCE() for the deletion flag updates because the cache check reads flags without taking state_lock.
Which versions are affected by CVE-2026-98699?
How do I fix CVE-2026-98699?
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-2026-98699 being exploited?
There is no known exploitation of CVE-2026-98699 in the wild and no public exploit code.
Sources
Also known as AZL-109239, BELL-CVE-2026-98699, DEBIAN-CVE-2026-98699, GHSA-5j8p-334x-vh85, UBUNTU-CVE-2026-98699.