CVE-2023-54035 netfilter: nf_tables: fix underflow in chain reference counter
A double decrement of the chain reference counter in Linux kernel netfilter can cause an underflow, potentially leading to a denial of service.
- 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-2023-54035?
CVE-2023-54035 is a high-severity vulnerability in Linux, published on 24 Dec 2025. 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: fix underflow in chain reference counter
Set element addition error path decrements reference counter on chains twice: once on element release and again via nft_data_release().
Then, d6b478666ffa ("netfilter: nf_tables: fix underflow in object reference counter") incorrectly fixed this by removing the stateful object reference count decrement.
Restore the stateful object decrement as in b91d90368837 ("netfilter: nf_tables: fix leaking object reference count") and let nft_data_release() decrement the chain reference counter, so this is done only once.
Which versions are affected by CVE-2023-54035?
How do I fix CVE-2023-54035?
Apply the vendor's patch.
Is CVE-2023-54035 being exploited?
There is no known exploitation of CVE-2023-54035 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54035, DEBIAN-CVE-2023-54035, GHSA-pcf2-g46w-wp92, ROOT-OS-DEBIAN-11-CVE-2023-54035, ROOT-OS-UBUNTU-2204-CVE-2023-54035, UBUNTU-CVE-2023-54035.