# CVE-2026-30521: Business logic in n/a

> An authenticated attacker can create loan plans with negative interest rates by bypassing client-side validation, impacting financial data integrity.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Mar 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-pmwx-37w8-6v99

## What is CVE-2026-30521?

CVE-2026-30521 is a medium-severity vulnerability in n/a, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-602 (Client-Side Enforcement of Server-Side Security)

## Which versions are affected by CVE-2026-30521?

It affects 1 product.


Products: Oretnom23 Loan Management System.

## How do I fix CVE-2026-30521?

No fix has been published for CVE-2026-30521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-30521 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30521 exists.

## Other vulnerabilities in n/a

- [CVE-2026-30522](https://insights.sbomify.com/CVE-2026-30522/): Business logic in n/a (medium 6.5)
- [CVE-2026-30523](https://insights.sbomify.com/CVE-2026-30523/): Business logic in n/a (medium 6.5)
- [CVE-2026-30520](https://insights.sbomify.com/CVE-2026-30520/): SQL injection in n/a (medium 5.4)
- [CVE-2026-3702](https://insights.sbomify.com/CVE-2026-3702/): SourceCodester Loan Management System index.php cross site scripting (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30521 and fix it if it is affected.

What it is: CVE-2026-30521 is a medium-severity vulnerability in n/a, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30521 exists.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-30521/ (Markdown: https://insights.sbomify.com/CVE-2026-30521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30521
- OSV: https://osv.dev/vulnerability/CVE-2026-30521

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30521/
Summaries are generated and may contain mistakes; the official description above is the record.