CVE-2026-29861 identifies a SQL injection vulnerability in PHP-MYSQL-User-Login-System v1.0 via the username parameter at login.php. The vulnerability allows remote attackers to inject malicious SQL queries without authentication, resulting in high impact on confidentiality, integrity, and availability. The CVSS 3.1 base score is 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). No patch or official remediation level has been provided by the vendor or authoritative sources as of the published date.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary SQL commands on the backend database, leading to unauthorized data disclosure, data modification, or deletion, and potentially full system compromise. The critical CVSS score reflects the high impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild to date.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider implementing input validation and parameterized queries as temporary mitigations to reduce risk. Monitor vendor channels for updates regarding patches or official mitigations.