CVE-2026-49416

The CONS_HISTORY ioctl handler did not adequately validate the requested history size.  A large value caused an integer overflow in the buffer size calculation, resulting in a heap allocation smaller than expected.  Subsequent initialization of the buffer wrote beyond the end of the allocation.

An unprivileged local user with access to a vt(4) device can trigger an out-of-bounds write in the kernel, potentially escalating privileges.