CVE-2026-27064
Received Received - Intake

Mailster <= 4.1.17 Arbitrary File Upload

Publication date: 2026-07-23

Last updated on: 2026-07-23

Assigner: Patchstack

Description
Editor Arbitrary File Upload in Mailster <= 4.1.17 versions.

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Meta Information

Published
2026-07-23
Last Modified
2026-07-23
Generated
2026-07-23
AI Q&A
2026-07-23
EPSS Evaluated
N/A
NVD
CVE-2026-27064
EUVD
EUVD-2026-48151

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
patchstack mailster to 4.1.17 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-434 The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

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Executive Summary

This vulnerability is an arbitrary file upload issue in the WordPress Mailster Plugin versions 4.1.17 and below. It allows attackers with Editor or Developer privileges to upload malicious files, such as backdoors, to a website. The flaw was patched in version 4.1.18.

Detection Guidance

Check if the Mailster plugin version is 4.1.17 or below. Look for unexpected file uploads in the WordPress uploads directory. Use security plugins to scan for malicious files or unusual activity.

Impact Analysis

Attackers could exploit this to upload malicious files, potentially gaining control of your website. Such attacks are often used in mass campaigns targeting thousands of sites. Immediate update or mitigation is recommended.

Mitigation Strategies

Update the Mailster plugin to version 4.1.18 or later immediately. If updating is not possible, apply Patchstack's mitigation rule to block attacks until the update is applied.

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