CVE-2026-68126 mac802154: hold an interface reference across the scan worker
A use-after-free in the Linux kernel mac802154 scan worker allows local attackers with CAP_NET_ADMIN to execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68126?
CVE-2026-68126 is an use after free vulnerability in Linux, published on 10 Aug 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:
mac802154: hold an interface reference across the scan worker
mac802154_scan_worker() captures the scanning sub-interface under RCU and then keeps dereferencing sdata->dev after rcu_read_unlock() and outside the rtnl -- in the failure traces, in mac802154_transmit_beacon_req() (skb->dev = sdata->dev), and in the end_scan cleanup. Nothing keeps that netdev alive across the worker iteration.
A concurrent DEL_INTERFACE or PHY removal can unregister the interface once the worker drops the rtnl between its two drv_set_channel() sections. unregister_netdevice() frees the netdev asynchronously from netdev_run_todo() with the rtnl already dropped, so neither holding the rtnl nor the per-PHY IEEE802154_IS_SCANNING flag prevents a stale worker iteration from dereferencing the freed netdev -- a KASAN slab-use-after-free, reachable by racing TRIGGER_SCAN against DEL_INTERFACE (both CAP_NET_ADMIN).
Pin the netdev with netdev_hold() while the RCU read lock is still held, and release it at every worker exit.
Which versions are affected by CVE-2026-68126?
How do I fix CVE-2026-68126?
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-2026-68126 being exploited?
There is no known exploitation of CVE-2026-68126 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68126, DEBIAN-CVE-2026-68126, GHSA-qgwv-jp48-q22g, UBUNTU-CVE-2026-68126.