CVE-2026-31844: Authenticated SQL Injection in Koha displayby parameter of suggestion.pl

An authenticated SQL Injection vulnerability (CWE-89) exists in the Koha staff interface in the /cgi-bin/koha/suggestion/suggestion.pl endpoint due to improper validation of the displayby parameter used by the GetDistinctValues functionality. A low-privileged staff user can inject arbitrary SQL queries via crafted requests to this parameter, allowing execution of unintended SQL statements and exposure of sensitive database information. Successful exploitation may lead to full compromise of the backend database, including disclosure or modification of stored data.