CVE-2026-80519 ovpn: finish crypto callback cleanup before peer release
A use-after-free vulnerability in the Linux kernel's ovpn module allows attackers to cause denial of service or execute arbitrary code via improper peer reference handling.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80519?
CVE-2026-80519 is a critical use after free vulnerability in Linux, published on 26 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ovpn: finish crypto callback cleanup before peer release
Crypto completion callbacks hold both key-slot and peer references. The peer reference pins the netdev, and dropping the last peer reference can let netdev unregistration and module removal make progress.
Do not release that peer reference before the callback has finished its own cleanup. If ovpn_crypto_key_slot_put runs after ovpn_peer_put, it can schedule an RCU callback backed by module text after ovpn_cleanup rcu_barrier has already run. The TX error path also freed the remaining skb after ovpn_peer_put, leaving callback cleanup outside the peer/netdev lifetime window.
Release the key slot and free any remaining skb first, then drop the peer reference as the last callback action.
Which versions are affected by CVE-2026-80519?
How do I fix CVE-2026-80519?
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-2026-80519 being exploited?
There is no known exploitation of CVE-2026-80519 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80519, DEBIAN-CVE-2026-80519, GHSA-4qjp-chcx-vxh6, UBUNTU-CVE-2026-80519.