CVE-2026-46065 fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
A use-after-free in the Linux kernel's fbdev deferred I/O allows attackers to cause a denial of service or potentially execute code via device hot-unplug.
- 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-2026-46065?
CVE-2026-46065 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 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:
fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an instance as part of initializing deferred I/O and remove it only after the final mapping has been closed. If the fb_info and the contained deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info to invalidate the mapping. Any access will then result in a SIGBUS signal.
Fixes a long-standing problem, where a device hot-unplug happens while user space still has an active mapping of the graphics memory. The hot- unplug frees the instance of struct fb_info. Accessing the memory will operate on undefined state.
Which versions are affected by CVE-2026-46065?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46065?
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-2026-46065 being exploited?
There is no known exploitation of CVE-2026-46065 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88514, BELL-CVE-2026-46065, DEBIAN-CVE-2026-46065, GHSA-w279-mj9j-w893, ROOT-OS-DEBIAN-11-CVE-2026-46065, ROOT-OS-DEBIAN-12-CVE-2026-46065 and 3 more.