CVE-2026-44210Guest-to-Host Sandbox Escape in Kata Containers
Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. Versions prior to 3.31.0 ship with a default configuration that allows pod creators to inject arbitrary command-line arguments into the virtiofsd process through the `io.katacontainers.config.hypervisor.virtio_fs_extra_args` pod annotation. By injecting `-o source=/` along with `--no-announce-submounts` and `--sandbox=none`, an attacker can override the virtiofsd shared directory to serve the entire host root filesystem into the guest VM. Combined with the `kernel_params` annotation (also enabled by default) to activate the agent debug console, the attacker can mount the host filesystem from inside the VM and read or write any file on the host, including /etc/shadow. Version 3.31.0 patches the issue.
View on NVDAnalysis
Kata Containers versions prior to 3.31.0 contain a critical vulnerability allowing attackers to escape the VM sandbox. By exploiting pod annotations enabled by default, an attacker can gain full read/write access to the host filesystem from within a container, compromising the entire node.
Relevant roles
Severity
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCWE-88EPSS
Affects
katacontainers:kata_containersTechnical description
Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. Versions prior to 3.31.0 ship with a default configuration that allows pod creators to inject arbitrary command-line arguments into the virtiofsd process through the `io.katacontainers.config.hypervisor.virtio_fs_extra_args` pod annotation. By injecting `-o source=/` along with `--no-announce-submounts` and `--sandbox=none`, an attacker can override the virtiofsd shared directory to serve the entire host root filesystem into the guest VM. Combined with the `kernel_params` annotation (also enabled by default) to activate the agent debug console, the attacker can mount the host filesystem from inside the VM and read or write any file on the host, including /etc/shadow. Version 3.31.0 patches the issue.