CVE-2026-96566
Newsletter <= 9.4.0 - Unauthenticated Stored Cross-Site Scripting via 'np1' Custom Field Parameter
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.
INFO
Published Date :
Oct. 2, 2026, 8:17 a.m.
Last Modified :
Oct. 2, 2026, 8:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update 'The Newsletter' plugin to the latest version.
- Sanitize all user-supplied input.
- Escape all output to prevent script execution.
- Implement proper nonce and capability checks.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-96566.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-96566 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-96566
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-96566 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-96566 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Oct. 02, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96566.json">CVE-2026-96566</a> Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/classes.php#L212 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/module-base.php#L1032 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/includes/module.php#L1006 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/plugin.php#L457 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/profile/profile.php#L511 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/subscription/subscription.php#L257 Added Reference https://plugins.trac.wordpress.org/browser/newsletter/tags/9.3.9/subscription/subscription.php#L723 Added Reference https://plugins.trac.wordpress.org/changeset?reponame=&old=3711290%40newsletter&new=3711290%40newsletter Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/6e61119c-b83e-41b4-aa14-7dc61086520d?source=cve