If /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem.
For security reasons, container creation should be prohibited if /proc or /sys in the rootfs is a symbolic link.
I verified this behavior with youki.
When /proc or /sys is a symbolic link, runc fails to create the container, whereas youki successfully creates it.
This is the fix related to this issue in runc.
The following advisory appears to be related to this vulnerability:
{
"cwe_ids": [
"CWE-61"
],
"github_reviewed": true,
"github_reviewed_at": "2025-08-14T16:39:04Z",
"nvd_published_at": "2025-08-14T16:15:39Z",
"severity": "HIGH"
}