The getgrouplist function in the GNU C library (glibc) before version 2.3.5, when invoked with a zero argument, writes to the passed pointer even if the specified array size is zero, leading to a buffer overflow and potentially allowing attackers to corrupt memory.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.1% chance of exploitation in the next 30 days; higher than 81% of CVEs (scores of 2026-10-31)