CVE-2026-30521

A Business Logic vulnerability exists in SourceCodester Loan Management System v1.0 due to improper server-side validation. The application allows administrators to create "Loan Plans" with specific interest rates. While the frontend interface prevents users from entering negative numbers, this constraint is not enforced on the backend. An authenticated attacker can bypass the client-side restriction by manipulating the HTTP POST request to submit a negative value for the interest_percentage. This results in the creation of loan plans with negative interest rates.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/meifukun/Web-Security-PoCs/blob/main/Loan-Management-System/BusinessLogic-LoanPlan-NegativeInterest.md	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:oretnom23:loan_management_system:1.0:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-03-31 19:16

Updated : 2026-07-24 20:10

NVD link : CVE-2026-30521

Mitre link : CVE-2026-30521

CVE.ORG link : CVE-2026-30521

JSON object : View

Products Affected

oretnom23

loan_management_system

CWE

NVD-CWE-noinfo CWE-602

Client-Side Enforcement of Server-Side Security

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