WP Fastest Cache permits unauthenticated web-cache poisoning
WP Fastest Cache before 1.5.1 caches pages requested with certain tracking query parameters without incorporating those parameters into the cache key. An unauthenticated attacker can have a page rendered in the attacker's request context stored under the clean URL and served to subsequent visitors.
- Component
- WP Fastest Cache
- Plugin slug
wp-fastest-cache- Affected
- 0.8.7.7 to < 1.5.1
- Safe version
1.5.1- Published
- Sep 01, 2026
This CVE was published Sep 01, 2026 and is one of 34 known issues for this plugin.
Update, patch or deactivate.
Update to WP Fastest Cache 1.5.1 or later and purge existing page-cache entries after updating.
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.
Technical description
The WP Fastest Cache WordPress plugin before 1.5.1 does not include a set of tracking-related query parameters in its page-cache key while still caching pages requested with them, allowing unauthenticated attackers to have a page rendered under their own request context stored under, and served from, the clean URL's cache entry to every subsequent visitor.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N