WordPress security changelog
HIGH CVE-2026-83625 Deferred

Contact Form by Supsystic stores script from spoofed client-IP headers

Contact Form by Supsystic through 1.10.2 exposes updateNonce without authentication, allowing a visitor to obtain the nonce required for form submission. The attacker can submit a malicious value in a spoofable client-IP header such as X-Forwarded-For; the plugin stores it without sufficient sanitization or escaping and later executes it when the injected page is viewed.

CVE / CNA score 7.2 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Contact Form by Supsystic
Plugin slug
contact-form-by-supsystic
Affected
<= 1.10.2
Safe version
See mitigation notes
Published
Sep 05, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Sep 05, 2026 and is one of 11 known issues for this plugin.

What to do

Update, patch or deactivate.

This archive could not verify a fixed version from the official author release notes reviewed on 2026-10-13. Disable the affected feature or component where practical until remediation for the deployed configuration is established. restrict or disable affected forms until remediation is confirmed, and review stored submissions before privileged users view them. Official author release notes: https://wordpress.org/plugins/contact-form-by-supsystic/.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

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

The Contact Form by Supsystic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via IP Address Header in all versions up to, and including, 1.10.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. An unauthenticated attacker can first call the 'updateNonce' action — which is accessible without authentication due to its absence from the plugin's permission list — to obtain a valid nonce, then submit a contact form with a malicious payload in a spoofed IP header such as X-Forwarded-For.

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

References

Primary and upstream sources