CVE-2026-84042
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
In crun, when built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. This is a regression in crun 1.29 and affects crun >= 1.29.
Risk Assessment
An attacker able to supply a container image can gain root privileges on the host, leading to full compromise of the host system.
Recommendation
Update crun to a version that fixes the regression, or avoid rootful configurations with passt networking until a patch is available.
Other vulnerabilities in crun
See all- CVE-2026-88265Medium
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. 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-2026-88264Medium
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-2026-47766Medium
crun before version 1.28 contains a vulnerability in the default device setup that 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 default device nodes and stdio symlinks at the symlink target outside the container rootfs. This can lead to overwriting existing files, such as ptmx.
Original NVD description (English source)
A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29
Vulnerability data from NVD (NIST) · CISA KEV · EPSS