CVE-2026-96566 Newsletter <= 9.4.0 - Unauthenticated Stored Cross-Site Scripting via 'np1' Custom Field Parameter
Unauthenticated attackers can inject arbitrary scripts via the subscription endpoint, leading to code execution or account takeover when users view affected pages.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-96566?
CVE-2026-96566 is a high-severity cross-site scripting vulnerability in satollo Newsletter – Send awesome emails from WordPress, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-96566?
How do I fix CVE-2026-96566?
No fix has been published for CVE-2026-96566 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-96566 being exploited?
There is no known exploitation of CVE-2026-96566 in the wild and no public exploit code.
Sources
Also known as GHSA-5p9m-8jqc-cp3g.