CVE-2026-68397 net/iucv: take a reference on the socket found in afiucv_hs_rcv()
A use-after-free vulnerability in the Linux kernel's IUCV network module allows attackers to cause denial of service or execute arbitrary code via race conditions.
- 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-2026-68397?
CVE-2026-68397 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: take a reference on the socket found in afiucv_hs_rcv()
afiucv_hs_rcv() looks up the destination socket under iucv_sk_list.lock, drops the lock, and then passes the socket to the afiucv_hs_callback_*() handlers without holding a reference. AF_IUCV sockets are not RCU-protected and are freed synchronously by iucv_sock_kill() -> sock_put(), so a concurrent close can free the socket in the window between read_unlock() and the handler, which then dereferences freed memory (for example sk->sk_data_ready() in afiucv_hs_callback_syn()).
Take a reference with sock_hold() while the socket is still on the list and release it with sock_put() once the handler has run.
Weakness: CWE-416
Which versions are affected by CVE-2026-68397?
How do I fix CVE-2026-68397?
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-2026-68397 being exploited?
There is no known exploitation of CVE-2026-68397 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68397, DEBIAN-CVE-2026-68397, GHSA-7m4h-5x7q-hf25, UBUNTU-CVE-2026-68397.