CVE-2026-64473 vfio: Remove device debugfs before releasing devres
A use-after-free vulnerability in the Linux kernel VFIO driver allows local attackers to execute arbitrary code or escalate privileges via stale debugfs entries.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64473?
CVE-2026-64473 is an use after free vulnerability in Linux, published on 25 Jul 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:
vfio: Remove device debugfs before releasing devres
VFIO device debugfs files created with debugfs_create_devm_seqfile() store a devres allocated debugfs_devm_entry as inode private data. vfio_unregister_group_dev() currently calls vfio_device_del() before vfio_device_debugfs_exit(), but device_del() releases devres. This can leave debugfs entries visible with stale inode private data while unregister waits for userspace references to drain.
Remove the per-device debugfs tree before vfio_device_del(). The debugfs view is diagnostic only, so losing it at the start of unregister is preferable to preserving entries whose backing storage may already have been released.
Complete the teardown by clearing the per-device debugfs root after removal. This matches the global debugfs root cleanup and prevents future users from mistaking a removed dentry for a live debugfs tree during the remainder of unregister.
Which versions are affected by CVE-2026-64473?
How do I fix CVE-2026-64473?
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-2026-64473 being exploited?
There is no known exploitation of CVE-2026-64473 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-64473, DEBIAN-CVE-2026-64473, GHSA-fm4h-cjxv-2ppf, ROOT-OS-UBUNTU-2204-CVE-2026-64473, UBUNTU-CVE-2026-64473.