---
cve: "CVE-2026-56100"
severity: "HIGH"
cvss: 8.6
epss: "0.3%"
vendor: "SpringBlade"
kev: false
exploited: false
published: "2026-08-28 18:00:36"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T10:59:09+02:00"
---

# CVE-2026-56100

> 8.6 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- c69b9547c942c697da2f3ee6a9265b6004abd645 (Commit)

## Referenzen

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

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-56100) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_