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

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.

CVSS

7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Weakness (CWE)

CWE-200

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Wordfence

NVD analysis

Deferred

Record last updated

Apr 8, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.