CVE-2026-96566
Received Received - Intake

Stored XSS in The Newsletter WordPress Plugin

Publication date: 2026-10-02

Last updated on: 2026-10-02

Assigner: Wordfence

Description
The Newsletter – Send awesome emails from WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'np1' Custom Field Parameter in all versions up to, and including, 9.4.0 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. The subscription endpoint (na=sa) requires no nonce, no capability check, and no CAPTCHA, and the payload can be smuggled past email-address validation by embedding the {profile_1} placeholder in the local part of the submitted address, since WordPress's is_email() permits curly braces there.

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Meta Information

Published
2026-10-02
Last Modified
2026-10-02
Generated
2026-10-02
AI Q&A
2026-10-02
EPSS Evaluated
N/A
NVD
CVE-2026-96566
EUVD
EUVD-2026-91248

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
wordfence newsletter to 9.4.0 (inc)
wordpress newsletter to 9.4.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in The Newsletter – Send awesome emails from WordPress plugin for WordPress. It affects versions up to and including 9.4.0 due to insufficient input sanitization and output escaping in the 'np1' Custom Field Parameter. Unauthenticated attackers can inject malicious scripts into pages, which execute when users access those pages.

Detection Guidance

To detect this vulnerability, inspect WordPress sites using the Newsletter plugin version 9.4.0 or lower. Check for malicious scripts in the 'np1' custom field parameter or unusual payloads in subscription endpoints. Review server logs for requests to the 'na=sa' endpoint without proper authentication.

Impact Analysis

An attacker could steal user sessions, deface websites, or redirect users to malicious sites. Since the subscription endpoint lacks nonce, capability checks, and CAPTCHA, exploitation is easier. The vulnerability allows bypassing email validation using the {profile_1} placeholder, enabling script injection via crafted email addresses.

Compliance Impact

This vulnerability could lead to unauthorized data access or modification, violating GDPR's integrity and confidentiality principles. For HIPAA, it may risk protected health information exposure. Compliance failures could result in legal penalties, reputational damage, and loss of trust.

Mitigation Strategies

Update the Newsletter – Send awesome emails from WordPress plugin to the latest version, as the vulnerability exists in versions up to and including 9.4.0. Disable or restrict access to the subscription endpoint (na=sa) if possible until patched. Monitor for unusual activity or injected scripts in WordPress pages.

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