CVE-2026-105863: Payload authentication token field handling issue

Severity: Critical

CVSS Score: 9.2

Payload is a free and open source headless content management system. In versions after 3.0.0 and before 3.90.0, a custom field option that maps a field to a reserved authentication claim name can place unintended values in the authentication token issued at login. This issue is fixed in version 3.90.0.