What’s Vulnerable › Vulnerabilities

CVE-2026-96566: Newsletter <= 9.4.0 - Unauthenticated Stored Cross-Site Scripting via 'np1' Custom Field Parameter

• Severity: high (CVSS 7.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-03
• Weakness: CWE-79

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.

Affected products

• satollo Newsletter – Send awesome emails from WordPress: through 9.4.0

References

• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/classes.php#L212
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/module-base.php#L1032
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/module.php#L1006
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/plugin.php#L457
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/profile/profile.php#L511
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/subscription/subscription.php#L257
• https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/subscription/subscription.php#L723
• https://plugins.trac.wordpress.org/changeset?reponame=&old=3711290%40newsletter&new=3711290%40newsletter
• https://www.wordfence.com/threat-intel/vulnerabilities/id/6e61119c-b83e-41b4-aa14-7dc61086520d?source=cve

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