CVE-2026-5032 HIGH

CVE-2026-5032: W3 Total Cache <= 2.9.3 - Unauthenticated Security Token Exposure via User-Agent Header

Vendor Boldgrid
Product W3 Total Cache
Weakness CWE-200 · Info exposure
Published April 2, 2026
Last update April 8, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

The W3 Total Cache plugin for WordPress is vulnerable to information exposure in all versions up to, and including, 2.9.3. This is due to the plugin bypassing its entire output buffering and processing pipeline when the request's User-Agent header contains "W3 Total Cache", which causes raw mfunc/mclude dynamic fragment HTML comments — including the W3TC_DYNAMIC_SECURITY security token — to be rendered in the page source. This makes it possible for unauthenticated attackers to discover the value of the W3TC_DYNAMIC_SECURITY constant by sending a crafted User-Agent header to any page that contains developer-placed dynamic fragment tags, granted the site has the fragment caching feature enabled. With the leaked W3TC_DYNAMIC_SECURITY token, an attacker can craft valid mfunc tags to execute arbitrary PHP code on the server, achieving remote code execution.

Explanation of Vulnerability in Simple Terms

02Summary

W3 Total Cache versions up to 2.9.3 expose sensitive information that can be read over the network without authentication. An attacker can retrieve confidential data by sending requests to the affected plugin. No user interaction or special privileges are required. Update to a version newer than 2.9.3 to resolve this issue.

What an attacker can do

03Attacker Capabilities

Read sensitive information from the site without logging in.

Potential impact on your site

04Site Impact

Confidential data may be exposed to unauthenticated attackers, including cached content or configuration details.

Conditions required to exploit

05Prerequisites

Network access to the site; no authentication or user interaction required.

Key dates

06Disclosure timeline

April 2, 2026 CVE published
April 8, 2026 Record updated