Spring Boot : Insecure Temporary File Vulnerability - CVE-2026-40973

A local attacker on the same host as the application may be able to take control of the directory used by ApplicationTemp. When server.servlet.session.persistent is set to true and the attack persists across application restarts this may allow the attacker to read session information and hijack authenticated users or deploy a gadget chain and execute code as the applications user. Affected: Spring Boot 4.0.04.0.5 (fix 4.0.6) 3.5.03.5.13 (fix 3.5.14) 3.4.03.4.15 (fix 3.4.16) 3.3.0