CVE-2026-90421 PCI: Fix UAF when probe runs concurrent to dyn ID removal
A use-after-free vulnerability in the Linux kernel PCI subsystem allows local attackers to execute arbitrary code or escalate privileges during concurrent probe and ID removal operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90421?
CVE-2026-90421 is an use after free vulnerability in Linux, published on 17 Sep 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:
PCI: Fix UAF when probe runs concurrent to dyn ID removal
Dynamic IDs are only guaranteed to be valid when dynids.lock is held, as remove_id_store() can free the node. Thus, make a copy in pci_match_device(). Also, clarify that the id parameter is only valid during probe.
Which versions are affected by CVE-2026-90421?
How do I fix CVE-2026-90421?
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-2026-90421 being exploited?
There is no known exploitation of CVE-2026-90421 in the wild and no public exploit code.
Sources
Also known as AZL-102858, BELL-CVE-2026-90421, DEBIAN-CVE-2026-90421, GHSA-286w-pmvg-5rp9, UBUNTU-CVE-2026-90421.