CVE-2026-93821 PCI: altera: Protect root bus removal with rescan lock
A race condition in the Linux kernel PCI altera driver allows local attackers to trigger use-after-free errors, potentially causing system crashes or code execution.
- 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-2026-93821?
CVE-2026-93821 is an use after free vulnerability in Linux, published on 24 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: altera: Protect root bus removal with rescan lock
Hold the pci_rescan_remove_lock lock while stopping and removing a root bus to avoid racing with concurrent rescan or hotplug operations triggered via sysfs. Such races may lead to use-after-free issues or system crashes.
[bhelgaas: commit log]
Which versions are affected by CVE-2026-93821?
How do I fix CVE-2026-93821?
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-2026-93821 being exploited?
There is no known exploitation of CVE-2026-93821 in the wild and no public exploit code.
Sources
Also known as AZL-103823, BELL-CVE-2026-93821, DEBIAN-CVE-2026-93821, GHSA-4f4q-pcpx-7p8f, UBUNTU-CVE-2026-93821.