What is CVE-2026-87920?

CVE-2026-87920 is a high-severity vulnerability in Boldgrid W3 Total Cache, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-10-02.

How severe is CVE-2026-87920?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Boldgrid W3 Total Cache

CVE-2026-87920

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-10-02 · last modified 2026-10-02.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Boldgrid W3 Total Cache

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-87920?: CVE-2026-87920 is a high-severity vulnerability in Boldgrid W3 Total Cache, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-10-02.
How severe is CVE-2026-87920?: High severity. CVSS v3 base score is 7.2 out of 10.