CVE-2026-47243
Published:August 07, 2026
Updated:September 01, 2026
Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. Prior to 3.31.0, the runtime-rs standalone virtio-fs path is vulnerable to a guest-root to host-root escape. In this configuration, Kata runs the host virtiofsd as root with --sandbox none --seccomp none, so an attacker with root-equivalent access inside the guest can bypass the guest virtio-fs client entirely by taking over the virtio-fs PCI device and building a virtqueue in userspace to submit raw FUSE requests directly to the host virtiofsd. A crafted FUSE_SYMLINK request whose new symlink name is an absolute host path is honored outside the configured shared directory, allowing guest root to create root-owned symlinks in sensitive host locations such as /etc/cron.d. By pointing such a symlink at a guest-controlled crontab payload reachable through a live runtime process's mount namespace, the attacker causes the host cron daemon to execute that payload as host root, crossing the Kata isolation boundary. This issue is fixed in version 3.31.0.
Affected Packages
https://github.com/kata-containers/kata-containers.git (GITHUB):
Affected version(s) >=release-3.4.0 <3.31.0Fix Suggestion:
Update to version 3.31.0Related Resources (7)
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Contact UsCVSS v4
Base Score:
9.2
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
Exploit Maturity
POC
CVSS v3
Base Score:
7.9
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.18