Information disclosure in Boldgrid W3 Total Cache

CVE-2026-5032

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.

Vulnerability class: Information Disclosure

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.032 (88.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-5032: rose from 0.027 to 0.032.

EPSS over last 30 days · oldest: 0.027 · newest: 0.032 · change: +0.006

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5032?
CVE-2026-5032 is a high-severity vulnerability in Boldgrid W3 Total Cache, classified under Information Disclosure. CVSS score: 7.5/10. Published 2026-04-02.
How severe is CVE-2026-5032?
High severity. CVSS v3 base score is 7.5 out of 10.