CISA Adds Actively Exploited Linux Root Access Bug CVE-2026-31431 to KEV

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added CVE-2026-31431, a Linux root access bug also known as Copy Fail, to its Known Exploited Vulnerabilities catalog due to active exploitation. This privilege escalation flaw allows unprivileged local users to gain root access by corrupting the kernel’s page cache, posing a significant risk to cloud and containerized environments.