CVE-2026-98708 wifi: mac80211: keep paired old chanctx alive
A use-after-free in the Linux kernel Wi-Fi subsystem allows attackers to cause denial of service or potentially execute code via crafted wireless operations.
- 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-2026-98708?
CVE-2026-98708 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: keep paired old chanctx alive
An in-place replacement keeps reciprocal replace_ctx pointers between the old WILL_BE_REPLACED chanctx and the new REPLACES_OTHER chanctx. However, the early free paths only consider assigned and reserved link users when deciding whether to free the old chanctx.
That lets the old chanctx be freed too early while the replacement partner still points back to it, either when the last assigned link is released or when that link successfully reassigns to another existing context. Later unreserve and switch-finalization paths can then follow a stale replace_ctx pointer.
Keep a paired old chanctx alive until the replacement pair has been torn down. Apply the same check to both __ieee80211_link_release_channel() and ieee80211_link_use_reserved_reassign(). If the replacement is later abandoned, ieee80211_link_unreserve_chanctx() already tears down the pairing before freeing the old chanctx once no users remain.
Which versions are affected by CVE-2026-98708?
How do I fix CVE-2026-98708?
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-2026-98708 being exploited?
There is no known exploitation of CVE-2026-98708 in the wild and no public exploit code.
Sources
Also known as AZL-108608, BELL-CVE-2026-98708, DEBIAN-CVE-2026-98708, GHSA-84vh-fqvc-p664, UBUNTU-CVE-2026-98708.