How Cloudflare responded to the “Copy Fail” Linux vulnerability

2026-06-24

Cloudflare details its response to the "Copy Fail" Linux kernel vulnerability, a local privilege escalation bug in the AF_ALG crypto interface. Their strategy involved identifying exposed kernels, confirming exploit detection, deploying an eBPF-based policy to restrict AF_ALG socket binds, and rolling out patched LTS kernels.