CVE-2026-72383 sctp: fix addr_wq_timer race in sctp_free_addr_wq()
A race condition in the Linux kernel SCTP subsystem allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- 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-2026-72383?
CVE-2026-72383 is a high-severity use after free vulnerability in Linux, published on 15 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:
sctp: fix addr_wq_timer race in sctp_free_addr_wq()
sctp_free_addr_wq() previously removed addr_wq_timer using timer_delete() while holding addr_wq_lock. However, timer_delete() does not guarantee that a currently running timer handler has completed.
This allows a race with sctp_addr_wq_timeout_handler(), where the handler may still run after addr_waitq has been freed, acquire addr_wq_lock, and access freed memory, leading to a use-after-free.
Fix this by calling timer_shutdown_sync() before taking addr_wq_lock. This guarantees that any in-flight timer handler has finished and prevents the timer from being re-armed during teardown, making subsequent cleanup safe.
Which versions are affected by CVE-2026-72383?
How do I fix CVE-2026-72383?
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-2026-72383 being exploited?
There is no known exploitation of CVE-2026-72383 in the wild and no public exploit code.
Sources
Also known as AZL-96570, BELL-CVE-2026-72383, DEBIAN-CVE-2026-72383, GHSA-8hr4-pprj-6g53, UBUNTU-CVE-2026-72383.