CVE-2021-43816: Fedoraproject Fedora

Critical severity, CVSS 9.1. EPSS: 1.7% chance of exploitation in the next 30 days.

containerd is an open source container runtime. On installations using SELinux, such as EL8 (CentOS, RHEL), Fedora, or SUSE MicroOS, with containerd since v1.5.0-beta.0 as the backing container runtime interface (CRI), an unprivileged pod scheduled to the node may bind mount, via hostPath volume, any privileged, regular file on disk for complete read/write access (sans delete). Such is achieved by placing the in-container location of the hostPath volume mount at either `/etc/hosts`, `/etc/hostname`, or `/etc/resolv.conf`. These locations are being relabeled indiscriminately to match the container process-label which effectively elevates permissions for savvy containers that would not normally be able to access privileged host files. This issue has been resolved in version 1.5.9. Users are advised to upgrade as soon as possible.

Affected products

• Fedoraproject Fedora: version 34 only; version 35 only
• Linuxfoundation Containerd: from 1.5.1, before 1.5.9 (fixed in 1.5.9); version 1.5.0 only

Published 2022-01-05. Last modified 2026-06-17.