CVE-2026-47243

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-07 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-09 21:02 UTC Last updatedMost recent change to the record

Details

Published

2026-08-07 22:16 UTC

Last modified

2026-09-09 21:02 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-22 · Path traversal

Record status

Deferred

Attack profile CVSS 4.0 · 9.2

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

High

User interaction

None

Confidentiality

High

Integrity

High

Availability

None