WordPress Simple PayPal Shopping Cart <= 5.1.3 — Insecure Direct Object Reference via 'quantity'
CVE-2025-3889Published · Updated Action summary
Affected: ≤5.1.3Update to 5.1.4 or newer
All remediation steps- Severity
- Medium5.3
- CVSS
- 5.3CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:NConfidentiality- None
I:LIntegrity- Low
A:NAvailability- None
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
Simple Shopping Cart wordpress-simple-paypal-shopping-cart
- Affected≤ 5.1.3
- Patched in5.1.4
Update to 5.1.4 or newer.
You are affected if you run ≤ 5.1.3. Version 5.1.4 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Simple Shopping Cart.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 5.1.4, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Simple Shopping Cart to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Jack Taylor.
The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'process_payment_data' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Simple Shopping Cart
All 15| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium4.3 | 5.3.2 - Authenticated (Contributor+) Payment Bypass 5.1.3 – 5.3.2Update to 5.3.3 | CVE-2026-104642 | |
| Medium5.3 | Unauthenticated Payment Bypass ≤5.3.2Update to 5.3.3 | CVE-2026-104641 | |
| Medium4.4 | Authenticated (Administrator+) Stored Cross-Site Scripting ≤5.2.5Update to 5.2.6 | CVE-2026-104119 | |
| Medium5.3 | Unauthenticated Insecure Direct Object Reference ≤5.2.9Update to 5.3.0 | CVE-2026-48868 | |
| Medium6.4 | Authenticated (Contributor+) Stored Cross-Site Scripting via 'wpsc_display_product' Shortcode ≤5.2.4Update to 5.2.5 | CVE-2026-0552 |
- Medium4.35.3.2 - Authenticated (Contributor+) Payment Bypass
5.1.3 – 5.3.2Update to 5.3.3
- Medium5.3Unauthenticated Payment Bypass
≤5.3.2Update to 5.3.3
- Medium4.4Authenticated (Administrator+) Stored Cross-Site Scripting
≤5.2.5Update to 5.2.6
- Medium5.3Unauthenticated Insecure Direct Object Reference
≤5.2.9Update to 5.3.0
- Medium6.4Authenticated (Contributor+) Stored Cross-Site Scripting via 'wpsc_display_product' Shortcode
≤5.2.4Update to 5.2.5
Timeline
CVE published
Severity medium, CVSS 5.3
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.