CVE-2026-72066 cpu: hotplug: Bound hotplug states sysfs output
A buffer overflow in the Linux kernel CPU hotplug sysfs output allows attackers to cause denial of service or execute code.
- 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-2026-72066?
CVE-2026-72066 is a high-severity memory corruption 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:
cpu: hotplug: Bound hotplug states sysfs output
states_show() adds CPU hotplug state names into a single sysfs buffer using sprintf(). With enough registered states, this can write past the end of the PAGE_SIZE buffer.
Use sysfs_emit_at() so output is bounded.
Weakness: CWE-120
Which versions are affected by CVE-2026-72066?
How do I fix CVE-2026-72066?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72066 being exploited?
There is no known exploitation of CVE-2026-72066 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72066, DEBIAN-CVE-2026-72066, GHSA-58q4-579w-9x9r, UBUNTU-CVE-2026-72066.