CVE-2026-18917 Libvirt: integer overflow in nodegetfreepages rpc handler leading to heap buffer overflow

High 7.8 Published Updated

An integer overflow in libvirt's NodeGetFreePages RPC handler allows local attackers to trigger a heap buffer overflow, potentially causing denial of service or privilege escalation.

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-2026-18917?

CVE-2026-18917 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 20 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A flaw was found in libvirt. An unprivileged local user could exploit an integer overflow vulnerability in the NodeGetFreePages RPC handler. This flaw allows crafted values to bypass a size check, leading to an undersized memory buffer. Subsequently, real NUMA node data can overwrite this buffer. This heap buffer overflow can corrupt the root libvirt daemon's memory, potentially leading to a denial of service or local privilege escalation.

Weakness: CWE-190

Which versions are affected by CVE-2026-18917?

Linux distribution packages (40)
libvirt Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-client Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-client-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-client-qemu Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-common Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-common-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-config-network Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-config-nwfilter Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-interface Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-interface-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-network Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-network-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-nodedev Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-nodedev-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-nwfilter Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-nwfilter-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-qemu Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-qemu-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-secret Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-secret-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-core Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-core-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-disk Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-disk-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-iscsi Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-iscsi-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-logical Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-logical-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-mpath Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-mpath-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-rbd Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-rbd-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-scsi Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-driver-storage-scsi-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-kvm Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-lock Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0
libvirt-daemon-lock-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:10.10.0-8.12.el10_0

How do I fix CVE-2026-18917?

Apply the vendor's patch.

Is CVE-2026-18917 being exploited?

There is no known exploitation of CVE-2026-18917 in the wild and no public exploit code.

Sources

Also known as AZL-97485, BELL-CVE-2026-18917, DEBIAN-CVE-2026-18917, GHSA-6jq9-9f7w-h7mc, RHSA-2026:68509, RHSA-2026:68510 and 3 more.

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