ZcopyReaper Is in RDS Zerocopy. User Namespaces Will Not Save You
CVE-2026-43502 is a local root in the RDS zerocopy path, present since Linux 4.17. Mainline fix is 7.1-rc3. Ubuntu lists 7.0.0-28, 6.8.0-136, and 5.15.0-186. Restricting user namespaces does nothing.