---
id: CVE-2026-56100
title: >-
  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 int…
summary: >-
  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 int…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-862
published: '2026-08-28'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T13:42:45.543'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56100'
references:
  - url: >-
      https://gist.github.com/sud0why/e73405057dd7414a8c221ef17e0d0059#file-cve-2026-56100-springblade-authbypass-en-md
    label: disclosure@vulncheck.com
  - url: 'https://github.com/chillzhuang/SpringBlade'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/chillzhuang/SpringBlade/commit/c69b9547c942c697da2f3ee6a9265b6004abd645
    label: disclosure@vulncheck.com
  - url: 'https://github.com/chillzhuang/SpringBlade/releases#release-v5.0.0'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/springblade-privilege-escalation-via-exposed-feign-endpoint
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00525
epssPercentile: 0.42007
ingestedAt: '2026-08-30T07:49:06.431Z'
vendor: SpringBlade
product: SpringBlade
affected:
  - SpringBlade >= 2.7.3 < 5.0.0
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-28T20:29:59.660106Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.