USN-8833-1

It was discovered that libvirt did not properly validate newline characters in DNS TXT record values and SRV record attributes in its virtual network driver. A local attacker with permission to define virtual networks could possibly use this issue to inject arbitrary dnsmasq configuration directives, leading to arbitrary command execution as root. (CVE-2026-61477)

It was discovered that libvirt did not properly handle errors during XML context parsing. An attacker could possibly use this issue to cause libvirt to crash, resulting in a denial of service. (CVE-2026-61478)

He Wei discovered that libvirt had a symlink-following vulnerability in the file ownership change function used for virtual TPM state directories. A local attacker running as the swtpm user could possibly use this issue to cause libvirt to change the ownership of an arbitrary file, leading to privilege escalation. (CVE-2026-63622)

It was discovered that libvirt created storage volume images with overly permissive permissions during clone or convert operations. A local attacker could possibly use this issue to read guest disk contents, resulting in information disclosure. (CVE-2026-63623)

It was discovered that libvirt had an integer overflow in the NodeGetFreePages RPC handler. A local attacker could possibly use this issue to cause libvirt to crash or execute arbitrary code. (CVE-2026-18917)

It was discovered that libvirt had a symlink-following flaw in the virtual TPM emulator setup function. A local attacker with access to the swtpm account could possibly use this issue to cause libvirt to change the ownership of an arbitrary file, leading to privilege escalation. (CVE-2026-77159)

References

Affected packages

Ubuntu:26.04:LTS / libvirt-hwe

Package

Name: libvirt-hwe
Purl: pkg:deb/ubuntu/libvirt-hwe?arch=source&distro=resolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

12.0.0-1ubuntu5.5

Affected versions

12.*

12.0.0-1ubuntu5

12.0.0-1ubuntu5.1

12.0.0-1ubuntu5.2

12.0.0-1ubuntu5.3

Ecosystem specific

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libnss-libvirt-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-clients-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-clients-qemu-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-common-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-common-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-config-network-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-config-nwfilter-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-interface-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-lxc-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-network-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-nodedev-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-nwfilter-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-qemu-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-secret-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-disk-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-gluster-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-iscsi-direct-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-iscsi-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-logical-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-mpath-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-rbd-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-scsi-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-storage-zfs-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-vbox-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-driver-xen-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-lock-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-log-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-plugin-lockd-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-plugin-sanlock-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-system-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-system-systemd-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-daemon-system-sysv-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-dev-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-doc-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-l10n-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-login-shell-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-sanlock-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-ssh-proxy-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt-wireshark-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        },
        {
            "binary_name":  "libvirt0-hwe",
            "binary_version":  "12.0.0-1ubuntu5.5"
        }
    ]
}

Database specific

cves_map

{
    "cves":  [
        {
            "id":  "CVE-2026-18917",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        },
        {
            "id":  "CVE-2026-61477",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        },
        {
            "id":  "CVE-2026-61478",
            "severity":  [
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        },
        {
            "id":  "CVE-2026-63622",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        },
        {
            "id":  "CVE-2026-63623",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        },
        {
            "id":  "CVE-2026-77159",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem":  "Ubuntu:26.04:LTS"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8833-1.json"