CVE-2026-72435 netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
Incorrect RCU pointer assignment order in Linux kernel ipset allows use-after-free, potentially enabling local privilege escalation or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72435?
CVE-2026-72435 is a high-severity use after free vulnerability in Linux, published on 15 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:
netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
Sashiko pointed out that kfree_rcu() was called before rcu_assign_pointer() in handling the comment extension. Fix the order so that rcu_assign_pointer() called first.
Which versions are affected by CVE-2026-72435?
How do I fix CVE-2026-72435?
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-2026-72435 being exploited?
There is no known exploitation of CVE-2026-72435 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72435, DEBIAN-CVE-2026-72435, GHSA-g5m8-p567-grv6, UBUNTU-CVE-2026-72435.