CVE-2026-79602 x86: improper handling of HVM emulation return codes
A guest with an assigned PCI device can trigger a kernel bug in Xen, causing a denial of service.
- 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-2026-79602?
CVE-2026-79602 is a high-severity denial of service vulnerability in Xen, published on 8 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.
Weakness: CWE-119
Which versions are affected by CVE-2026-79602?
How do I fix CVE-2026-79602?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-79602 being exploited?
There is no known exploitation of CVE-2026-79602 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-79602, DEBIAN-CVE-2026-79602, GHSA-626m-h7vc-vwvc, UBUNTU-CVE-2026-79602.