The Linux kernel vulnerability identified as CVE-2026-74675 involves a race condition in the vt subsystem where the kbd_keycode() function reads the vc->port.tty pointer without acquiring a proper reference. This creates a race against con_shutdown(), which clears port.tty under a different lock, potentially leading to use-after-free or invalid pointer dereference. The vulnerability was resolved by modifying kbd_keycode() to use tty_port_tty_get() and tty_kref_put() to hold a stable reference to the tty pointer during its usage.

The vulnerability could lead to unstable behavior or kernel memory corruption due to racing access to the tty pointer without proper reference counting. This may affect system stability or security depending on how the race is triggered. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel to address this issue by using proper reference counting with tty_port_tty_get() and tty_kref_put(). Users should update to a kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; check the official Linux kernel advisories or vendor patches for the exact fixed versions and apply updates accordingly.