The read command is used to read the keyboard input from the user, while reads it keeps the input length in a 32-bit integer value which is further used to reallocate the line buffer to accept the next character. During this process, with a line big enough it's possible to make this variable to overflow leading to a out-of-bounds write in the heap based buffer. This flaw may be leveraged to corrupt grub's internal critical data and secure boot bypass is not discarded as consequence.
CVE-2025-0690
CVSS base score
6.1 (v3.1)
Severity
MEDIUM
Attack vector
Physical
Weakness
CWE-787
Last modified
November 5, 2026
CVSS vector
CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H