CVE-2026-56100

Description

SpringBlade versions 2.7.3 through 3.5.0 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.

References

• https://gist.github.com/sud0why/e73405057dd7414a8c221ef17e0d0059#file-cve-2026-56100-springblade-authbypass-en-md
• https://github.com/chillzhuang/SpringBlade
• https://github.com/chillzhuang/SpringBlade/commit/c69b9547c942c697da2f3ee6a9265b6004abd645
• https://github.com/chillzhuang/SpringBlade/releases#release-v5.0.0
• https://www.vulncheck.com/advisories/springblade-privilege-escalation-via-exposed-feign-endpoint