CVE-2026-48749: Incus is a system container and virtual machine manager. Prior to version 7.2.0, a specially crafted image can be used to read or create/wri

Executive brief

Incus, a container management platform, is vulnerable to a flaw where a specially crafted container image can bypass security boundaries. An attacker can use this to read or write any file on the physical host machine with root privileges. This could lead to a total system takeover, data theft, or permanent disruption of the host server.

Technical details

Incus is vulnerable to an arbitrary file read/write on the host due to improper validation of symlinks within container images. While Incus initially validates the image upon seeing 'metadata.yaml' and a 'rootfs/' directory, the extraction process can be manipulated to process a duplicate top-level 'rootfs' symlink pointing to the host's root directory. When the stopped-container file API later opens the rootfs path and passes it to 'forkfile' for a chroot operation, it follows the malicious symlink. This allows an authenticated attacker with image import privileges to access the host filesystem with root authority. The issue is fixed in version 7.2.0.

Affected products

• LXC Incus < 7.2.0

Timeline

• 2026-06-25: disclosed
• 2026-06-26: advisory
• 2026-06-26: patched: Version 7.2.0 released

References

• https://api.github.com/users/antifob
• https://github.com/antifob
• https://api.github.com/users/antifob/gists%7B/gist_id%7D
• https://api.github.com/users/antifob/repos
• https://avatars.githubusercontent.com/u/25389335?v=4
• https://api.github.com/users/antifob/events%7B/privacy%7D