CVE-2026-93053

In the Linux kernel, the following vulnerability has been resolved:

speakup: keyhelp: guard letter_offsets possible out-of-range indexing

help_init() builds letter_offsets[] by using the first byte of each

function name as an index via `(start & 31) - 1`. If function_names are

overridden from sysfs (root) with a name starting outside [a–z], the

index underflows or exceeds the array, leading to OOB write.

Function names can be overridden with the following commands as root:

modprobe speakup_soft

echo "0 _bad" > /sys/accessibility/speakup/i18n/function_names

# then press Insert+2 on /dev/tty

This fix checks the first letter in help_init(), and if it is not in the

[a–z] range the function returns an error to the caller. Eventually this

error is propagated to drivers/accessibility/speakup/main.c:2217, which

causes a bleep sound.