# CVE-2026-18917: Libvirt: integer overflow in nodegetfreepages rpc handler leading to heap buffer overflow > 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. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **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:** Yes - **Published:** 20 Aug 2026 - **Updated:** 5 Oct 2026 - **Also known as:** AZL-97485, BELL-CVE-2026-18917, DEBIAN-CVE-2026-18917, GHSA-6jq9-9f7w-h7mc, RHSA-2026:68509, RHSA-2026:68510, RHSA-2026:68511, RHSA-2026:68514, UBUNTU-CVE-2026-18917 ## 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 (Integer Overflow or Wraparound) ## Which versions are affected by CVE-2026-18917? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libvirt` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-client` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-client-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-client-qemu` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-common` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-common-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-config-network` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-config-nwfilter` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-interface` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-interface-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-network` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-network-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-nodedev` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-nodedev-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-nwfilter` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-nwfilter-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-qemu` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-qemu-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-secret` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-secret-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-core` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-core-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-disk` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-disk-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-iscsi` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-iscsi-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-logical` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-logical-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-mpath` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-mpath-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-rbd` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-rbd-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-scsi` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-driver-storage-scsi-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-kvm` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-lock` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.el10_0 | | `libvirt-daemon-lock-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:10.10.0-8.12.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. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-18917 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2026-18917 in the wild and no public exploit code. Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-18917/ (Markdown: https://insights.sbomify.com/CVE-2026-18917/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18917 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18917 - OSV: https://osv.dev/vulnerability/CVE-2026-18917 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-18917/ Summaries are generated and may contain mistakes; the official description above is the record.