CVE-2025-64203CWE-79

WordPress Mailster plugin < 4.1.14 - Cross Site Scripting (XSS) vulnerability

High · published December 18, 2025

CVSS v3.1
7.1
EPSS
0%
Percentile
11.8
In the wild
Unconfirmed
What it is

⚡ A crafty little Cross-Site Scripting (XSS) vulnerability in Mailster could let attackers execute their own scripts and hijack users’ sessions with just a click of a link! Think of it like a mischievous waiter who brings you a menu with hidden instructions—if you order the special, you might get served a surprise dish that alters your entire dining experience! An attacker could craft a malicious link that, when clicked by a user, runs unwanted scripts in their browser. This could lead to stolen cookies, session hijacking, or even defacing your web pages—quite the unwelcome surprise at dinner!

Put simply

Think of it like a mischievous waiter who brings you a menu with hidden instructions—if you order the special, you might get served a surprise dish that alters your entire dining experience! This reflected XSS vulnerability occurs due to improper neutralization of input during web page generation, allowing attackers to inject their own JavaScript into pages served to unsuspecting users.

What to do

An attacker could craft a malicious link that, when clicked by a user, runs unwanted scripts in their browser. This could lead to stolen cookies, session hijacking, or even defacing your web pages—quite the unwelcome surprise at dinner! Update Mailster to version 4.1.14 or later to patch this vulnerability. Additionally, implementing input validation and sanitization can help in mitigating XSS risks going forward. You've got this! Stay vigilant and secure your site with these updates! 🛡️

The record
Technical detail
CVSS v3.1
7.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
CVSS v4.0
Not supplied
EPSS
0.00219 · 11.8th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2025-12-18T07:22Z
EPSS history
Timeline
  • 18 DEC 07:22Z
    WordPress Mailster plugin < 4.1.14 - Cross Site Scripting (XSS) vulnerability
    cvelistv5