There was a flaw in the WordPress plugin, Email Subscribers & Newsletters before 4.3.1, that allowed SQL statements to be passed to the database in the hash parameter (a blind SQL injection vulnerability).

The Subscribe2 – Form, Email Subscribers & Newsletters plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ip parameter in all versions up to, and including, 10.43 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.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in AcyMailing Newsletter Team AcyMailing SMTP Newsletter allows Reflected XSS. This issue affects AcyMailing SMTP Newsletter: from n/a through n/a.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Tribulant Newsletters allows Reflected XSS. This issue affects Newsletters: from n/a through 4.9.9.6.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in SendPulse SendPulse Email Marketing Newsletter allows Stored XSS. This issue affects SendPulse Email Marketing Newsletter: from n/a through 2.1.5.

The WordPress Email Newsletter WordPress plugin through 1.1 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in NotFound EELV Newsletter allows Reflected XSS. This issue affects EELV Newsletter: from n/a through 4.8.2.

The Newsletter2Go plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the 'resetStyles' AJAX action in all versions up to, and including, 4.0.14. This makes it possible for authenticated attackers, with Subscriber-level access and above, to reset styles.

Cross-Site Request Forgery (CSRF) vulnerability in Automattic Newspack Newsletters allows Cross Site Request Forgery.This issue affects Newspack Newsletters: from n/a through 2.13.2.

Cross-Site Request Forgery (CSRF) vulnerability in Bastien Ho EELV Newsletter allows Cross Site Request Forgery.This issue affects EELV Newsletter: from n/a through 4.8.2.