Fixes available for CVE-2026-31431 (Copy Fail) Linux Kernel Local Privilege Escalation Vulnerability

A high-severity (CVSS 7.8) local privilege escalation vulnerability, CVE-2026-31431 (Copy Fail), has been disclosed in the Linux kernel's algif_aead module, which provides hardware-accelerated cryptographic functions. All Ubuntu releases before Resolute (26.04) are affected. The Ubuntu Security Team has released mitigations via the kmod package that disable the vulnerable module. A full kernel patch is also forthcoming. The post details how to check if your system is impacted, how to apply the kmod mitigation or manually block the module, and how to handle edge cases like running containers or applications that may not gracefully fall back to software cryptography.