An issue was discovered in phpMyAdmin. It is possible to bypass AllowRoot restriction ($cfg['Servers'][$i]['AllowRoot']) and deny rules for username by using Null Byte in the username. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.
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
2.7% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)