Mailster WordPress Newsletter Plugin
Mailster WordPress Newsletter Plugin has 6 disclosed vulnerabilities in the WordSec catalog, reported between 2020 and 2026; all 6 are fixed as of October 2026. Their average CVSS score is 7.1, and the most serious one scores 9.8 out of 10. Severity breakdown: 1 critical and 2 high. 2024 was the busiest year with 3 disclosures.
The most common weakness is Cross-Site Scripting, behind 4 of the records (67%). Other recurring categories include PHP Remote File Inclusion, Unrestricted Upload Of File With Dangerous Type.
Every one of the 6 issues recorded for Mailster WordPress Newsletter Plugin has a vendor fix available, so running the current release closes all known holes.
5 independent researchers contributed these findings, most of them (2) reported by Rafie Muhammad. Mailster WordPress Newsletter Plugin is installed on roughly 7,000 WordPress sites, so each unpatched flaw has a wide blast radius. The current release is tested up to WordPress 7.1.3.
CVE-2024-32523Mailster <= 4.0.6 - Unauthenticated Local File Inclusion
Read the full analysisVulnerability Records

Mailster WordPress Newsletter Plugin
Author
EverPress
This free plugin is a Mailster compatibility tester Mailster itself is a premium-only WordPress email newsletter and email marketing plugin. It is not distributed as a free download on WordPress.org. This listing installs a free compatibility tester under the mailster plugin slug. Use it to verify that your WordPress site and hosting environment are ready for Mailster before you purchase a license. After you activate the tester, open Mailster Tester in the WordPress admin and run the checks. The tester reviews: PHP and WordPress version requirements Required PHP capabilities (DOMDocument, fsockopen) Memory limit recommendations Whether wp_mail() can deliver a test message Whether common SMTP-related TCP ports (25, 465, 587, 993, 2525) are reachable When you are ready, get the full Mailster plugin from mailster.co. Why choose Mailster for WordPress email newsletters? Mailster is an easy-to-use email newsletter plugin for WordPress. Create, send, and track newsletter campaigns without a separate ESP account for your subscriber list—your data stays in your own WordPress database. Capture subscribers and grow your list Collect subscribers with signup forms on your website or blog. Import existing lists, manage unlimited subscribers, forms, and lists on a one-time license model (support and updates require an active license period). Send posts, products, and custom content Send your latest posts, WooCommerce products, events, or other custom post types as newsletters. The same content types can drive email automation. Automate welcome series, drips, and follow-ups Set up welcome emails, birthday campaigns, drip campaigns, follow-ups, auto-responders, and more. Mailster can run targeted journeys while you focus on your business. Templates and campaign editor Choose from more than 400 free and premium email templates. Build campaigns quickly with Mailster’s editor, or adapt designs with Mailster’s template markup language. Deliverability and sending flexibility Send with any email provider—professional SMTP/ESP services or your own server. Use RSS-to-email to turn new posts from a feed into automated campaigns. Time zone based sending helps reach subscribers when they are most likely to open. Personalization, segmentation, and insights Use merge tags for personalized content, segment audiences with Mailster’s metrics, and track opens, clicks, location, and other campaign activity in real time. Pre-check campaigns before you send so you can fix issues early. Privacy and control Mailster is designed for GDPR-conscious setups: subscriber data is stored in your WordPress database and is not handed to a third-party list host as the primary store. Capability management lets you control which team members can do what. Developers get hooks and filters to extend Mailster. Integrations and add-ons Mailster works alongside popular WordPress plugins and offers official add-ons. Browse templates, add-ons, and the knowledge base. Mailster feature highlights Subscriber capture forms and list management Campaigns for posts, products, and custom post types Welcome, birthday, drip, and follow-up automation 400+ free and premium templates RSS-to-email campaigns Built-in email campaign pre-check Send via any email provider / SMTP Time zone based delivery Merge tags and advanced segmentation Campaign insights and reports Public newsletter archive GDPR-oriented self-hosted data Capability management and developer hooks Available in many languages Important: Installing this WordPress.org plugin does not install the full premium Mailster product. Purchase and download Mailster from mailster.co after your environment passes the tester.
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