CVE-2026-72242 selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()
A null pointer dereference in the Linux kernel SCTP SELinux hook can cause a system crash when triggered via specific network packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72242?
CVE-2026-72242 is a high-severity vulnerability in Linux, published on 15 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:
selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()
selinux_sctp_bind_connect() dereferences sk->sk_socket to pass a struct socket * to selinux_socket_bind() and selinux_socket_connect_helper(). However, when the hook is invoked from the ASCONF softirq path (sctp_process_asconf), there is no file reference guaranteeing that sk->sk_socket is non-NULL. The setsockopt callers (bindx, connectx, set_primary, sendmsg connect) hold a file reference and are not affected.
Both selinux_socket_bind() and selinux_socket_connect_helper() immediately resolve sock->sk, never using the struct socket * for anything else. Refactor the inner logic into helpers that take a struct sock * directly so that selinux_sctp_bind_connect() never needs to touch sk->sk_socket at all.
Which versions are affected by CVE-2026-72242?
How do I fix CVE-2026-72242?
Apply the vendor's patch.
Is CVE-2026-72242 being exploited?
There is no known exploitation of CVE-2026-72242 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72242, DEBIAN-CVE-2026-72242, GHSA-v4p9-3h3v-9gpm, UBUNTU-CVE-2026-72242.