3728202 - Backoffice SSO fails with HTTP 500 after upgrade to 2211-jdk21.x

• After upgrading SAP Commerce Cloud to 2211-jdk21.x (Framework Update: Java JDK 21 and Spring 6.2), Single Sign-On to Backoffice returns HTTP 500 Internal Server Error.
• The same SSO configuration works on the previous (JDK 17–based) version.
• Logs/trace show failures similar to:
  • "java.lang.IllegalArgumentException: Failed to evaluate expression 'IS_AUTHENTICATED_FULLY'"
  • "org.springframework.expression.spel.SpelEvaluationException: Property or field 'IS_AUTHENTICATED_FULLY' cannot be found on object of type 'org.springframework.security.web.access.expression.WebSecurityExpressionRoot'"

SAP Commerce Cloud

SAP Commerce Cloud, Backoffice, SSO, SAML, OAuth, resource server, Spring Security 6, Java 21, JDK 21, JDK21, 2211-jdk21, IS_AUTHENTICATED_FULLY, use-expressions, use-authorization-manager, intercept-url, EL expressions, hasAuthority, hasRole, isFullyAuthenticated, oauth2 extension removal, authorization voters deprecated, HTTP 500, status code 500, response code 500, Internal Server Error, upgrade, framework update, spring security configuration , KBA , CEC-SCC-CDM-BO-FRW , Framework , Problem