Vulnerability · Published Aug 20, 2026 · Assigned by redhat

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

High 7.8

In plain English

A high-severity integer overflow in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 92.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
AlmaLinux:10	libvirt	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-client	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-client	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-client-qemu	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-client-qemu	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-common	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-common	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-config-network	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-config-network	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-config-nwfilter	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-config-nwfilter	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-interface	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-interface	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-network	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-network	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-nodedev	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-nodedev	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-nwfilter	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-nwfilter	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-qemu	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-qemu	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-secret	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-secret	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-core	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-core	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-disk	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-disk	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-iscsi	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-iscsi	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-logical	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-logical	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-mpath	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-mpath	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-rbd	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-rbd	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-driver-storage-scsi	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-driver-storage-scsi	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-kvm	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-kvm	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-lock	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-lock	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-log	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-log	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-plugin-lockd	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-plugin-lockd	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-plugin-sanlock	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-plugin-sanlock	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-daemon-proxy	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-daemon-proxy	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-devel	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-devel	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-docs	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-docs	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-libs	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-libs	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-nss	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-nss	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
AlmaLinux:10	libvirt-ssh-proxy	11.10.0-12.9.el10_2.alma.1	ALSA-2026:75583
AlmaLinux:9	libvirt-ssh-proxy	11.10.0-12.7.el9_8.alma.1	ALSA-2026:74424
Debian:12	libvirt	no fix listed	DEBIAN-CVE-2026-18917
Debian:13	libvirt	11.3.0-3+deb13u3	DEBIAN-CVE-2026-18917
Debian:14	libvirt	12.7.0-1	DEBIAN-CVE-2026-18917
Rocky Linux:10	libvirt	0:11.10.0-12.9.el10_2	RLSA-2026:75583
Rocky Linux:9	libvirt	0:11.10.0-12.7.el9_8	RLSA-2026:74424
Ubuntu:22.04:LTS	libvirt	8.0.0-1ubuntu7.21	UBUNTU-CVE-2026-18917
Ubuntu:22.04:LTS	libvirt	8.0.0-1ubuntu7.21	USN-8831-1
Ubuntu:24.04:LTS	libvirt	10.0.0-2ubuntu8.19	UBUNTU-CVE-2026-18917
Ubuntu:24.04:LTS	libvirt	10.0.0-2ubuntu8.19	USN-8831-1
Ubuntu:26.04:LTS	libvirt	12.0.0-1ubuntu5.5	USN-8831-1
Ubuntu:26.04:LTS	libvirt	12.0.0-1ubuntu5.5	UBUNTU-CVE-2026-18917
Ubuntu:26.04:LTS	libvirt-hwe	12.0.0-1ubuntu5.5	UBUNTU-CVE-2026-18917
Ubuntu:26.04:LTS	libvirt-hwe	12.0.0-1ubuntu5.5	USN-8833-1

Affected products (as reported)

Vendor	Product	Versions
Red Hat	Red Hat Enterprise Linux 10	see references
Red Hat	Red Hat Enterprise Linux 10.0 Extended Update Support	see references
Red Hat	Red Hat Enterprise Linux 7 Extended Lifecycle Support	see references
Red Hat	Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support	see references
Red Hat	Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On	see references
Red Hat	Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support	see references
Red Hat	Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On	see references
Red Hat	Red Hat Enterprise Linux 8.8 Telecommunications Update Service	see references
Red Hat	Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions	see references
Red Hat	Red Hat Enterprise Linux 9	see references
Red Hat	Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions	see references
Red Hat	Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions	see references
Red Hat	Red Hat Enterprise Linux 9.6 Extended Update Support	see references
Red Hat	Red Hat Enterprise Linux 6	see references
Red Hat	Red Hat Enterprise Linux 8	see references
Red Hat	Red Hat Enterprise Linux for NVIDIA 26	see references

Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

RHSA-2026:68509 vendor-advisory, x_refsource_REDHAT
RHSA-2026:68510 vendor-advisory, x_refsource_REDHAT
RHSA-2026:68511 vendor-advisory, x_refsource_REDHAT
RHSA-2026:68513 vendor-advisory, x_refsource_REDHAT
RHSA-2026:68514 vendor-advisory, x_refsource_REDHAT
RHSA-2026:68594 vendor-advisory, x_refsource_REDHAT
RHSA-2026:69114 vendor-advisory, x_refsource_REDHAT
RHSA-2026:69131 vendor-advisory, x_refsource_REDHAT
RHSA-2026:74424 vendor-advisory, x_refsource_REDHAT
RHSA-2026:75583 vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-18917 vdb-entry, x_refsource_REDHAT
RHBZ#2520161 issue-tracking, x_refsource_REDHAT