Newsletters <= 4.17 - Missing Authorization to Authenticated (Author+) Arbitrary Modification via 'newsletters_mailinglistsroles' POST Parameter
Strategic Overview
- Status
- Patched in 4.18
- Affected Plugin
- Newsletters
- Affected Version
<= 4.17- CVSS
- 4.3Medium
- Weakness type
- CWE-862 · Missing Authorization
- CVE
CVE-2026-75908
At a glance
CVE-2026-75908 is a medium-severity Missing Authorization vulnerability in the Newsletters WordPress plugin, affecting versions <= 4.17. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Author level or above. The issue is fixed in version 4.18; sites on affected versions should update now. Disclosed August 2026, reported by Wordfence PRISM.
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-862: Missing Authorization
Newsletters <= 4.17 carries this weakness at get_users(), and reaching it takes an account at Author level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.
Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Newsletters the fix is 4.18: builds <= 4.17 are affected, anything from 4.18 onward is not.
Remediation
Update to version 4.18, or a newer patched version
How does WordSec protect against this?
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Newsletters 4.18 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in Newsletters
- 9.8CVE-2018-20987: Newsletters <= 4.6.8.5 Object Injection
CVE-2018-20987 - 9.1CVE-2024-32954: Newsletters <= 4.9.5 Arbitrary File Upload
CVE-2024-32954 - 8.8CVE-2024-8247: Newsletters <= 4.9.9.2 Privilege Escalation
CVE-2024-8247 - 8.8CVE-2019-14788: Newsletters <= 4.6.18 Directory Traversal
CVE-2019-14788 - 8.1CVE-2026-16267: Newsletters <= 4.15 PHP Object Injection
CVE-2026-16267 - 8.1CVE-2026-12583: Newsletters <= 4.14 PHP Object Injection
CVE-2026-12583 - 8.1CVE-2025-67911: Newsletters <= 4.11 PHP Object Injection
CVE-2025-67911 - 8.1CVE-2025-54034: Newsletters <= 4.10 Local File Inclusion
CVE-2025-54034
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C