Is CVE-2026-18328 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-18328 being exploited in the wild.

How severe is CVE-2026-18328?

High severity, with a CVSS score of 7.2, published 25 August 2026.

Which products and versions are affected?

WPMU DEV Forminator up to and including 1.57.0.

Is there a fix for CVE-2026-18328?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-18328 attacked?

It is attacked over the network.

Am I affected by CVE-2026-18328?

Check whether you run WPMU DEV Forminator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-18328: Forminator DOM-based reflected XSS in Stripe Checkout parameter

CVE-2026-18328 · Severity: high · CVSS 7.2 · Published 2026-08-25

Forminator is a popular WordPress form builder plugin used to create contact forms, payment forms, and custom forms on websites. A flaw in how it processes Stripe payment API parameters allows attackers to inject malicious scripts into pages, which execute when users visit a link containing the payload. This could lead to account takeover, credential theft, or malware distribution on affected websites.

Technologies: WPMU DEV Forminator. Vendors: WPMU DEV.

Quick answers

Is CVE-2026-18328 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-18328 being exploited in the wild.
How severe is CVE-2026-18328?: High severity, with a CVSS score of 7.2, published 25 August 2026.
Which products and versions are affected?: WPMU DEV Forminator up to and including 1.57.0.
Is there a fix for CVE-2026-18328?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-18328 attacked?: It is attacked over the network.
Am I affected by CVE-2026-18328?: Check whether you run WPMU DEV Forminator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a DOM-based reflected cross-site scripting (XSS) flaw in the 'error_description' parameter used by the Stripe Checkout Sessions payment API integration. The plugin fails to properly sanitize and escape this parameter before rendering it in the DOM, allowing unauthenticated attackers to inject arbitrary JavaScript. The vulnerability is triggered only on pages hosting a Forminator form configured to use Stripe Checkout Sessions (the default since version 1.56.0). An attacker crafts a malicious URL containing XSS payload in the error_description parameter; when a user clicks the link, the script executes in their browser with the user's privileges. No patch version is publicly confirmed yet; users should upgrade from 1.57.0 or earlier.

Affected products

WPMU DEV Forminator up to and including 1.57.0

Timeline

2026-08-25: disclosed

References

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