Threat Intelligence Database

A flaw was found in crun. When the container configuration does not give /dev a dedicated mount, terminal setup can redirect /dev/console onto an attacker-controlled path, including via the read-only-rootfs bind-mount fallback. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.

CVE-2026-88265 is a moderate security flaw in crun affecting versions 1.29.1 and earlier. The vulnerability allows a non-root container process to follow a symlink when reopening /dev/null after pivot_root, potentially attaching a host file to container stdio and changing its ownership. This requires specific conditions, such as a malicious container image replacing /dev/null with a symlink and the container not mounting a fresh /dev. No fixed release is currently available, and default configurations that mount a fresh /dev are not exposed to this issue.

CVE-2026-84042 is a high-severity vulnerability in crun affecting versions 1.29 and later. When crun is built with libkrun and a container is started rootful with passt networking enabled (krun.use_passt), it can execute attacker-controlled payloads from the container image with host root privileges. This is a regression introduced in crun 1.29. The issue involves improper privilege management, allowing privilege escalation to host root. Mitigation currently involves avoiding running untrusted container images with krun and passt networking until a fixed version is released.

crun is an open source OCI Container Runtime fully written in C. Prior to version 1.28, crun's default device setup opens the container rootfs `/dev` directory without `O_NOFOLLOW`. If an OCI bundle contains `rootfs/dev` as a symlink and the bundle configuration does not mount `/dev`, crun follows that symlink and creates the default device nodes and stdio symlinks at the symlink target outside the container rootfs. In a local rootful crun replay, this created fixed device nodes and symlinks outside the rootfs before crun returned failure. A pre-existing file named `ptmx` in the target directory was also replaced by crun's forced `ptmx -> pts/ptmx` symlink. Version 1.28 fixes the issue.