CVE-2025-67911 CRITICAL

CVE-2025-67911: WordPress Newsletters plugin <= 4.11 - PHP Object Injection vulnerability

Vendor Tribulant Software
Product Newsletters
Weakness CWE-502 · Unsafe deserialization
Published January 8, 2026
Last update April 28, 2026
View on NVD All CVEs

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

Deserialization of Untrusted Data vulnerability in Tribulant Software Newsletters newsletters-lite allows Object Injection.This issue affects Newsletters: from n/a through <= 4.11.

Explanation of Vulnerability in Simple Terms

02Summary

Tribulant Newsletters versions 4.11 and earlier contain a deserialization vulnerability that allows unauthenticated attackers to run arbitrary code on the site without user interaction. The vulnerability exists in how the plugin processes untrusted serialized data. An attacker can exploit this remotely over the network to gain full control of the affected site.

What an attacker can do

03Attacker Capabilities

Run arbitrary code on the site and take complete control without needing to log in.

Potential impact on your site

04Site Impact

Complete site compromise: attackers can steal data, modify content, install malware, or take the site offline.

Conditions required to exploit

05Prerequisites

Network access only; no authentication or user interaction required.

Key dates

06Disclosure timeline

January 8, 2026 CVE published
April 28, 2026 Record updated