CVE-2026-87920 W3 Total Cache <= 2.10.6 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Unauthenticated attackers can inject arbitrary scripts via comment content in W3 Total Cache when a specific option is enabled, leading to stored XSS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-87920?
CVE-2026-87920 is a high-severity cross-site scripting vulnerability in boldgrid W3 Total Cache, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-87920?
How do I fix CVE-2026-87920?
No fix has been published for CVE-2026-87920 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-87920 being exploited?
There is no known exploitation of CVE-2026-87920 in the wild and no public exploit code.
Sources
Also known as GHSA-pv8h-wp6c-44p7.