CVE-2026-56100

CVE-2026-56100 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. SpringBlade versions from 2.7.3 up to but not including 5.0.0 contain a privilege escalation vulnerability that allows authenticated attackers to create system administrator accounts by sending crafted POST requests to an unprotected internal Feign user-creation endpoint exposed via @RestController without authorization checks. Attackers can exploit the gateway's authentication filter, which only validates JWT parsing without verifying user roles or caller identity, and leverage a hardcoded JWT signing key embedded in publicly available JARs to forge tokens and escalate privileges from a low-privilege user to administrator, enabling cross-tenant data pollution and persistent backdoor access.. EPSS estimates a 0.29% chance of exploitation in the next 30 days.