CVE-2026-23412 netfilter: bpf: defer hook memory release until rcu readers are done
A use-after-free vulnerability in the Linux kernel netfilter BPF subsystem allows local attackers to potentially execute code or escalate privileges via concurrent hook dumping.
- 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-2026-23412?
CVE-2026-23412 is a high-severity use after free vulnerability in Linux kernel, published on 2 Apr 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: bpf: defer hook memory release until rcu readers are done
Yiming Qian reports UaF when concurrent process is dumping hooks via nfnetlink_hooks:
BUG: KASAN: slab-use-after-free in nfnl_hook_dump_one.isra.0+0xe71/0x10f0 Read of size 8 at addr ffff888003edbf88 by task poc/79 Call Trace: <TASK> nfnl_hook_dump_one.isra.0+0xe71/0x10f0 netlink_dump+0x554/0x12b0 nfnl_hook_get+0x176/0x230 [..]
Defer release until after concurrent readers have completed.
Weakness: CWE-416
Which versions are affected by CVE-2026-23412?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23412?
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-2026-23412 being exploited?
There is no known exploitation of CVE-2026-23412 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23412, DEBIAN-CVE-2026-23412, GHSA-4jr5-4pj9-2xj8, ROOT-OS-DEBIAN-13-CVE-2026-23412, ROOT-OS-UBUNTU-2404-CVE-2026-23412, UBUNTU-CVE-2026-23412.