CVE-2026-4987

SureForms <= 2.5.2 - Unauthenticated Payment Amount Validation Bypass via 'form_id'

2026-03-27 12:56
AlexHenry

Strategic Overview

Status
Patched in 2.6.0
Affected Plugin
SureForms – Contact Form Builder, AI Forms, Payment Form, Survey & Quiz
Affected Version
<= 2.5.2
CVSS
7.5High
Weakness type
CWE-20 · Improper Input Validation
CVE
CVE-2026-4987
View all SureForms – Contact Form Builder, AI Forms, Payment Form, Survey & Quiz vulnerabilities

At a glance

CVE-2026-4987 is a high-severity Improper Input Validation vulnerability in the SureForms WordPress plugin, affecting versions <= 2.5.2. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high integrity impact). Exploitation requires no authentication. The issue is fixed in version 2.6.0; sites on affected versions should update now. Disclosed March 2026, reported by AlexHenry.

Vulnerability Overview

The SureForms – Contact Form, Payment Form & Other Custom Form Builder plugin for WordPress is vulnerable to Payment Amount Bypass in all versions up to, and including, 2.5.2. This is due to the create_payment_intent() function performing a payment validation solely based on the value of a user-controlled parameter. This makes it possible for unauthenticated attackers to bypass configured form payment-amount validation and create underpriced payment/subscription intents by setting form_id to 0.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on integrity.

CWE-20: Improper Input Validation

SureForms <= 2.5.2 carries this weakness at create_payment_intent(), and reaching it takes no account at all. Improper input validation means the application accepts input without confirming it has the form, type or range the code downstream assumes.

The concrete impact depends on where the unvalidated value lands, which is why records in this class range from cosmetic bugs to full compromise. For SureForms the fix is 2.6.0: builds <= 2.5.2 are affected, anything from 2.6.0 onward is not.

Remediation

Update to version 2.6.0, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: SureForms 2.6.0 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-4987https://www.wordfence.com/threat-intel/vulnerabilities/id/c4772b32-a730-44f2-b43c-f9bd5abb6541https://nvd.nist.gov/vuln/detail/CVE-2026-4987

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C