CVE-2026-75908: Newsletters <= 4.17 - Missing Authorization to Authenticated (Author+) Arbitrary Modification via 'newsletters_mailinglistsroles' POST Parameter

Vulnerability summary

CVE-2026-75908 is a medium (CVSS 4.3) Missing Authorization vulnerability in contrid newsletters. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.4% of scored vulnerabilities. Fixed in 4.18.

Timeline

1. 25-08-2026
   PublishedVulnerability first disclosed.
2. 25-08-2026
   Last modifiedVulnerability information updated.

Description

The Newsletters plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.17. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with author-level access and above, to send arbitrary newsletter emails to users of any WordPress role, including administrators, by forging POST fields during a normal post submission. This allows an attacker-supplied role slug via the newsletters_mailinglistsroles POST field to be passed directly to get_users(), enabling unauthorized mass-mailing and potential phishing against privileged site users through the site's own outbound email channel.

• CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.