CVE-2026-56100

SpringBlade 2.7.3 < 5.0.0 Privilege Escalation via Exposed Feign Endpoint

HIGH
8.1
CVSS Score
Published: August 28, 2026 at 06:00 PM UTC
Updated: October 1, 2026 at 03:20 PM UTC
2 products affected across 2 vendorsSpringbladeSpringBlade

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Severity
HIGH8.1
Exploit prediction
EPSS 0.5%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.7.3 ≤ v < 5.0.0
Affected range stops below 5.0.0, so it looks safe — our inference, not a vendor statement
2.7.3 ≤ v < 5.0.02.7.3
Affected range stops below 5.0.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

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