CVE-2026-30951: Sequelize v6 Vulnerable to SQL Injection via JSON Column Cast Type

SQL injection via unescaped cast type in JSON/JSONB where clause processing. The _traverseJSON() function splits JSON path keys on :: to extract a cast type, which is interpolated raw into CAST(... AS <type>) SQL. An attacker who controls JSON object keys can inject arbitrary SQL and exfiltrate data from any table.

Affected: v6.x through 6.37.7. v7 (@sequelize/core) is not affected.