CVE-2026-68342 ovpn: avoid putting unrelated P2P peer on socket release
A use-after-free in the Linux kernel OVPN module allows local attackers to execute code or escalate privileges via socket release race conditions.
- 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-2026-68342?
CVE-2026-68342 is an use after free vulnerability in Linux, published on 10 Aug 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:
ovpn: avoid putting unrelated P2P peer on socket release
ovpn_peer_release_p2p() is called when an OVPN UDP socket is being destroyed. It checks the currently published P2P peer and releases it only if that peer still uses the socket being destroyed.
A peer replacement can publish a new peer before the old UDP socket is destroyed. When the old socket destruction path runs afterwards, ovpn_peer_release_p2p() observes the new peer through ovpn->peer. Since the new peer uses a different socket, the function takes the socket mismatch branch.
That branch still calls ovpn_peer_put(peer). At this point, however, peer is the currently published replacement peer, not the peer associated with the socket being destroyed. Dropping its reference can free it while ovpn->peer still points to it, leading to later use-after-free accesses from the peer and socket cleanup paths.
KASAN reports this as a slab-use-after-free on the kmalloc-1k ovpn_peer object. In the reproducer, the object is allocated from ovpn_peer_new() via ovpn_nl_peer_new_doit(), and freed through ovpn_peer_release_rcu() from RCU callback processing. Observed access sites include ovpn_peer_remove(), ovpn_socket_release(), ovpn_nl_peer_del_notify(), and unlock_ovpn().
Fix this by returning from the socket mismatch branch without putting the peer.
Which versions are affected by CVE-2026-68342?
How do I fix CVE-2026-68342?
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-2026-68342 being exploited?
There is no known exploitation of CVE-2026-68342 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68342, DEBIAN-CVE-2026-68342, GHSA-wh63-3892-rjx3, UBUNTU-CVE-2026-68342.