CVE-2026-68140 net/iucv: fix use-after-free of a severed iucv_path
A use-after-free in the Linux kernel's IUCV network module allows attackers to cause denial of service or potentially execute code via crafted network messages.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68140?
CVE-2026-68140 is a high-severity 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:
net/iucv: fix use-after-free of a severed iucv_path
af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() -- a use-after-free of the freed iucv_path.
Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued.
Weakness: CWE-416
Which versions are affected by CVE-2026-68140?
How do I fix CVE-2026-68140?
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-2026-68140 being exploited?
There is no known exploitation of CVE-2026-68140 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68140, DEBIAN-CVE-2026-68140, GHSA-8p4m-4f3f-9xqp, UBUNTU-CVE-2026-68140.