Improper Input Validation in PayPal Payment Button Plugin by WordPress
CVE-2026-16990

5.3MEDIUM

Key Information:

Vendor

WordPress
Status
Payment Button For Paypal
Vendor
CVE Published:
12 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-16990?

The Payment Button for PayPal WordPress plugin prior to version 1.2.3.44 features a significant vulnerability related to improper input validation. This security flaw allows unauthenticated users to manipulate the payment amount by sending a client-supplied payment value that is not properly validated server-side. As a result, attackers can create fraudulent PayPal orders for an amount significantly lower than intended by the merchant, potentially leading to financial losses.

Affected Version(s)

Payment Button for PayPal 0 <= 1.2.3.44

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-16990 - Proof of Concept

References

https://wpscan.com/vulnerability/97c08603-c407-43b2-ab2c-...
exploitvdb-entrytechnical-description

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Muni Nitish Kumar Yaddala
WPScan
.