W3 Total Cache: Stored XSS through comment URL rewriting

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. No further endpoint or implementation detail is disclosed beyond the path described here. The official changelog confirms a matching fix in 2.10.7.

CVE / CNA score 7.2 CVSS 3.1 · security@wordfence.com

NVD score Pending NVD has not published its own CVSS assessment.

Component: W3 Total Cache
Plugin slug: w3-total-cache
Affected: <= 2.10.6
Safe version: 2.10.7
Published: Oct 02, 2026
Weakness: CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Oct 02, 2026 and is one of 25 known issues for this plugin.

What to do

Update, patch or deactivate.

Update W3 Total Cache to 2.10.7 or a later supported release. Disable Remove query strings from static resources until updated. Parse HTML attributes structurally and preserve attribute boundaries when rewriting URLs. Official changelog: https://wordpress.org/plugins/w3-total-cache/#developers.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

References

Primary and upstream sources

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