7.2
HIGH CVSS 3.1
CVE-2026-87920
W3 Total Cache <= 2.10.6 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Description

The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via Output-Buffer Regex Rewrite in all versions up to, and including, 2.10.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability is only exploitable when the 'Remove query strings from static resources' option is enabled in W3 Total Cache, as mutate_url() must strip the '?' delimiter and everything following it — including the closing quote of the outer attribute — to break the attribute boundary.

INFO

Published Date :

Oct. 2, 2026, 10:17 a.m.

Last Modified :

Oct. 2, 2026, 10:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-87920 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Boldgrid w3_total_cache
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
Solution
Update W3 Total Cache plugin to version 2.10.7 or later to fix Stored Cross-Site Scripting.
  • Update the W3 Total Cache plugin to version 2.10.7 or later.
  • Ensure 'Remove query strings from static resources' option is disabled.
  • Sanitize all user-provided input thoroughly.
  • Escape all output dynamically displayed on web pages.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-87920 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-87920 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-87920 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-87920 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 02, 2026

    Action Type Old Value New Value
    Added Description The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via Output-Buffer Regex Rewrite in all versions up to, and including, 2.10.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability is only exploitable when the 'Remove query strings from static resources' option is enabled in W3 Total Cache, as mutate_url() must strip the '?' delimiter and everything following it — including the closing quote of the outer attribute — to break the attribute boundary.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/87xxx/CVE-2026-87920.json">CVE-2026-87920</a>
    Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L208
    Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L259
    Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L336
    Added Reference https://plugins.trac.wordpress.org/changeset/3723494/w3-total-cache/trunk/BrowserCache_Plugin.php
    Added Reference https://plugins.trac.wordpress.org/changeset?reponame=&new=3723494%40w3-total-cache%2Ftags%2F2.10.7&old=3681561%40w3-total-cache%2Ftags%2F2.10.6
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/34bd7c32-f4c5-4015-909a-e4730f35494b?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.