USN-8833-1: libvirt vulnerabilities

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)