CVE-2026-23001 macvlan: fix possible UAF in macvlan_forward_source()
A use-after-free vulnerability in the Linux kernel macvlan driver allows attackers to potentially 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-2026-23001?
CVE-2026-23001 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jan 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:
macvlan: fix possible UAF in macvlan_forward_source()
Add RCU protection on (struct macvlan_source_entry)->vlan.
Whenever macvlan_hash_del_source() is called, we must clear entry->vlan pointer before RCU grace period starts.
This allows macvlan_forward_source() to skip over entries queued for freeing.
Note that macvlan_dev are already RCU protected, as they are embedded in a standard netdev (netdev_priv(ndev)).
https: //lore.kernel.org/netdev/[email protected]/T/#u
Weakness: CWE-416
Which versions are affected by CVE-2026-23001?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23001?
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-2026-23001 being exploited?
There is no known exploitation of CVE-2026-23001 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-77169, BELL-CVE-2026-23001, DEBIAN-CVE-2026-23001, GHSA-vgc7-m4r9-xw45, ROOT-OS-DEBIAN-11-CVE-2026-23001, ROOT-OS-DEBIAN-12-CVE-2026-23001 and 4 more.