self-hosting
Copy Fail: A 4-Byte Page-Cache Write, and What It Does to Your Rootless Homelab
Copy Fail (CVE-2026-31431) lets any local user write 4 bytes into the page cache of any readable file, and one 732-byte script turns that into root. Container isolation never touched the page cache: rootless Podman stops the root, not the poisoned binary your other containers execute.