CVE-2026-98235 net/sched: act_api: release tail references on DELACTION failure
A reference counting bug in the Linux kernel's traffic control API can lead to memory corruption and potential privilege escalation or denial of service.
- 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-2026-98235?
CVE-2026-98235 is a memory corruption vulnerability in Linux, published on 6 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:
net/sched: act_api: release tail references on DELACTION failure
A batched RTM_DELACTION request takes a temporary reference on each action before attempting any deletion. tcf_action_delete() clears each processed slot and drops its temporary reference before attempting the deletion. If deletion fails, tca_action_gd() calls tcf_action_put_many() to release the remaining references, but its tcf_act_for_each_action() iterator stops at the first NULL slot.
When a batch stops at an action bound to a filter, this leaks a reference on each subsequent action. A later delete of an unbound action can then return success without removing it from the IDR.
Walk the full array in tcf_action_put_many() and skip NULL slots to release the references held on the unprocessed actions.
Which versions are affected by CVE-2026-98235?
How do I fix CVE-2026-98235?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98235 being exploited?
There is no known exploitation of CVE-2026-98235 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98235, DEBIAN-CVE-2026-98235, GHSA-2gfh-v7wp-gcg2, UBUNTU-CVE-2026-98235.