CVE-2022-50212 netfilter: nf_tables: do not allow CHAIN_ID to refer to another table
A use-after-free vulnerability in the Linux kernel netfilter subsystem allows local attackers to execute arbitrary code or escalate privileges.
- 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-2022-50212?
CVE-2022-50212 is a high-severity use after free vulnerability in Linux kernel, published on 18 Jun 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: do not allow CHAIN_ID to refer to another table
When doing lookups for chains on the same batch by using its ID, a chain from a different table can be used. If a rule is added to a table but refers to a chain in a different table, it will be linked to the chain in table2, but would have expressions referring to objects in table1.
Then, when table1 is removed, the rule will not be removed as its linked to a chain in table2. When expressions in the rule are processed or removed, that will lead to a use-after-free.
When looking for chains by ID, use the table that was used for the lookup by name, and only return chains belonging to that same table.
Weakness: CWE-416
Which versions are affected by CVE-2022-50212?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50212?
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-2022-50212 being exploited?
There is no known exploitation of CVE-2022-50212 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50212, GHSA-6qc3-mmcj-4p92, ROOT-OS-UBUNTU-2204-CVE-2022-50212, UBUNTU-CVE-2022-50212.