Business Logic Vulnerability in SourceCodester Loan Management System
CVE-2026-30521

6.5MEDIUM

Key Information:

Vendor

SourceCodester
Status
Loan Management System
Vendor
CVE Published:
31 March 2026

What is CVE-2026-30521?

A business logic vulnerability has been identified in SourceCodester Loan Management System v1.0, arising from inadequate server-side validation. Although the application’s frontend is designed to prevent users from entering negative numbers for setting interest rates, this validation is not effectively enforced on the server side. As a result, an authenticated attacker can exploit this flaw by manipulating HTTP POST requests to submit negative values for the interest_percentage. Consequently, this allows the creation of loan plans that carry negative interest rates, potentially causing severe financial discrepancies.

References

https://github.com/meifukun/Web-Security-PoCs/blob/main/L...

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.