CVE-2026-23278 netfilter: nf_tables: always walk all pending catchall elements
A use-after-free in Linux kernel netfilter allows local attackers to cause a system crash via crafted netlink transactions.
- 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-2026-23278?
CVE-2026-23278 is a high-severity use after free vulnerability in Linux kernel, published on 20 Mar 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: nf_tables: always walk all pending catchall elements
During transaction processing we might have more than one catchall element: 1 live catchall element and 1 pending element that is coming as part of the new batch.
If the map holding the catchall elements is also going away, its required to toggle all catchall elements and not just the first viable candidate.
Otherwise, we get: WARNING: ./include/net/netfilter/nf_tables.h:1281 at nft_data_release+0xb7/0xe0 [nf_tables], CPU#2: nft/1404 RIP: 0010:nft_data_release+0xb7/0xe0 [nf_tables] [..] __nft_set_elem_destroy+0x106/0x380 [nf_tables] nf_tables_abort_release+0x348/0x8d0 [nf_tables] nf_tables_abort+0xcf2/0x3ac0 [nf_tables] nfnetlink_rcv_batch+0x9c9/0x20e0 [..]
Weakness: CWE-416
Which versions are affected by CVE-2026-23278?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23278?
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-2026-23278 being exploited?
There is no known exploitation of CVE-2026-23278 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-80207, BELL-CVE-2026-23278, DEBIAN-CVE-2026-23278, GHSA-5vxp-pqjj-287g, ROOT-OS-DEBIAN-11-CVE-2026-23278, ROOT-OS-DEBIAN-12-CVE-2026-23278 and 4 more.