Quick PayPal Payments: Payment Button & Form: Cross-site scripting

The Quick PayPal Payments: Payment Button & Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'form' parameter in all versions up to, and including, 6.0.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Because wp_kses_post strips only HTML tags, a quote-breaking payload containing no angle brackets survives post save intact, and the injected script fires for every viewer of the post — including higher-privileged Editors and Administrators who routinely preview a Contributor's pending content. The export supplies no additional endpoint, action, parameter or function details beyond those described above.

CVE / CNA score 6.4 CVSS 3.1 · security@wordfence.com

NVD score Pending NVD has not published its own CVSS assessment.

Component: Quick PayPal Payments: Payment Button & Form
Plugin slug: quick-paypal-payments
Affected: <= 6.0.4
Safe version: 6.0.5
Published: Oct 16, 2026
Weakness: CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Oct 16, 2026 and is one of 9 known issues for this plugin.

What to do

Update, patch or deactivate.

Update Quick PayPal Payments: Payment Button & Form to 6.0.5 or a later supported release in the applicable branch. The official author release notes confirm this fixed version for the disclosed issue. Official release notes: https://fullworksplugins.com/docs/quick-paypal-payments/installation-quick-paypal-payments/change-log-qpp/.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

References

Primary and upstream sources

Data attribution: This product uses the NVD API but is not endorsed or certified by the NVD.

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