Vulnerability · Published Aug 28, 2026 · Assigned by VulnCheck
CVE-2026-56100SpringBlade 2.7.3 < 5.0.0 Privilege Escalation via Exposed Feign Endpoint
High 8.1
In plain English
A high-severity missing authorization in SpringBlade from SpringBlade. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| SpringBlade | SpringBlade | 2.7.3 – before 5.0.0 |
Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
- Researcher Disclosure technical-description, exploit
- https://github.com/chillzhuang/SpringBlade/releases#release-v5.0.0
- Patch Commit patch
- SpringBlade GitHub Repository product
- https://www.vulncheck.com/advisories/springblade-privilege-escalation-via-exposed-feign-endpoint third-party-advisory