CVE-2026-0665 Qemu-kvm: heap off-by-one in kvm xen physdevop_map_pirq
A malicious guest can trigger heap out-of-bounds access in QEMU via Xen hypercalls, causing denial of service or potential code execution.
- 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-2026-0665?
CVE-2026-0665 is a medium-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 18 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption.
Weakness: CWE-787
Which versions are affected by CVE-2026-0665?
Linux distribution packages (5)
qemu SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 9.2.4-150700.3.14.1 |
qemu SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 9.2.4-150700.3.14.1 |
qemu-linux-user SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 9.2.4-150700.3.14.1 |
qemu SUSE:Linux Enterprise Module for Server Applications 15 SP7 | All versions | 9.2.4-150700.3.14.1 |
qemu openSUSE:Tumbleweed | All versions | 10.2.0-2.1 |
How do I fix CVE-2026-0665?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-0665 being exploited?
There is no known exploitation of CVE-2026-0665 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-0665, DEBIAN-CVE-2026-0665, GHSA-4pq4-6gr5-cr69, OESA-2026-1352, SUSE-SU-2026:0445-1, UBUNTU-CVE-2026-0665 and 1 more.