CVE-2026-72283 KVM: x86: Nullify irqfd->producer if updating IRTE for bypass fails
A use-after-free in KVM x86 allows attackers to execute arbitrary code or escalate privileges via dangling pointers in irqfd handling.
- 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-2026-72283?
CVE-2026-72283 is a high-severity use after free 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:
KVM: x86: Nullify irqfd->producer if updating IRTE for bypass fails
Nullify irqfd->producer if updating the IRTE for bypass fails, as leaving a dangling pointer will result in a use-after-free if the irqfd is reachable through KVM's routing, but the producer is freed separately. E.g. for VFIO PCI, the producer is embedded in struct "vfio_pci_irq_ctx" and freed when the vector is disabled, which can happen independent of routing updates.
[sean: drop PPC change, massage changelog]
Which versions are affected by CVE-2026-72283?
How do I fix CVE-2026-72283?
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-2026-72283 being exploited?
There is no known exploitation of CVE-2026-72283 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72283, DEBIAN-CVE-2026-72283, GHSA-ww73-cj9w-h762, UBUNTU-CVE-2026-72283.