Copy Fail Bug Lets 732 Bytes Hijack Linux Root

A new vulnerability, the Copy Fail bug (CVE-2026-31431), has emerged, posing a significant threat to Linux systems. This alarming exploit allows an ordinary user to acquire root access by executing a compact 732-byte script. Notably, it requires no race conditions or luck to work effectively on prominent distributions such as Ubuntu, RHEL, and SUSE. The exploit operates by subtly altering the page cache rather than the disk file itself, effectively bypassing integrity checks while enabling the kernel to execute the modified version in memory.

Moreover, the shared nature of the page cache allows this exploit to cross container boundaries, significantly expanding its potential impact. Administrators are urged to patch their systems promptly if their distribution has not already addressed this vulnerability. As security experts express concern over the exploit’s reliability, prompt action remains crucial to mitigate potential risks.

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Copy Fail exploit lets 732 bytes hijack Linux systems and quietly grab root
byu/OkReport5065 innetsec