RHSA-2026:75583HighCVSS 7.8

Red Hat Security Advisory: libvirt security, bug fix, and enhancement update

Published
October 5, 2026
Last Modified
October 5, 2026

🔗 CVE IDs covered (2)

CVE-2026-63622 →CVE-2026-18917 →

📋 Description

CVE-2026-18917 — libvirt: Integer overflow in NodeGetFreePages RPC handler leading to heap buffer overflow CVE-2026-63622 — libvirt: swtpm privilege escalation via symlink following

🎯 Affected products200

  • Red Hat Enterprise Linux AppStream (v. 10)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • libvirt-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-0:11.10.0-12.9.el10_2.src as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-debuginfo-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • libvirt-client-qemu-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-qemu-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-client-qemu-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-common-0:11.10.0-12.9.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-common-0:11.10.0-12.9.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-common-0:11.10.0-12.9.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libvirt-daemon-common-0:11.10.0-12.9.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • +170 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Restrict access to the libvirt read-only Unix socket to limit which local users can reach the vulnerable RPC handler. In /etc/libvirt/libvirtd.conf, set unix_sock_ro_perms to "0770" (or "0700") and configure unix_sock_group to a group containing only trusted users. Alternatively, enable polkit authentication for the read-only socket by setting auth_unix_ro = "polkit", which requires callers to be authorized before any RPC dispatch occurs. After changing the configuration, restart the libvirtd service. Note: restricting socket access may prevent unprivileged monitoring tools or read-only management clients from connecting. Workaround: If virtual Trusted Platform Module (vTPM) functionality is not required, remove the <tpm> device definition from the domain XML configuration to prevent the vulnerable code path from being reached. To check if a domain uses vTPM: ``` virsh dumpxml <domain> | grep -A5 '<tpm' ``` To remove it, edit the domain XML and delete the <tpm> block. This prevents libvirt from spawning swtpm processes and from calling virFileChownFiles() on the swtpm state directory during domain startup. Domains that require vTPM for guest OS functionality cannot use this mitigation and should prioritize applying the upstream fix.

🔗 References (5)