CVE-2026-98709 wifi: mac80211: count only matching reservations in reserved switch
A use-after-free in the Linux kernel Wi-Fi subsystem allows attackers to cause denial of service or execute code via crafted channel context reservations.
- 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-2026-98709?
CVE-2026-98709 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: count only matching reservations in reserved switch
ieee80211_vif_use_reserved_switch() validates a replacement by counting assigned links on ctx->replace_ctx and treating reservations too broadly. A link can still be assigned to the old channel context while holding a reservation that belongs to a different replacement operation.
That can make the current replacement appear complete too early. If another link finalizes first, the function can free the WILL_BE_REPLACED chanctx while the unmatched link and driver still use it, leading to a use-after-free in later beacon generation.
Require an in-place reservation to point at the current replacement context, and require the reserved and assigned contexts to be the matching replacement pair, before counting or moving the link.
Which versions are affected by CVE-2026-98709?
How do I fix CVE-2026-98709?
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-2026-98709 being exploited?
There is no known exploitation of CVE-2026-98709 in the wild and no public exploit code.
Sources
Also known as AZL-108881, BELL-CVE-2026-98709, DEBIAN-CVE-2026-98709, GHSA-g34c-vjm7-4vq5, UBUNTU-CVE-2026-98709.