The vulnerability in Fastcache by Host.it allows an authenticated user with subscriber-level access or higher to bypass the plugin’s internal authorization checks. This bypass enables the attacker to add or remove the plugin’s page‑cache rewrite rules found in the site’s root .htaccess file. By manipulating these rules the attacker can alter request routing, potentially expose cached content, or disrupt normal page caching behavior, affecting the integrity and availability of the WordPress site.

WordPress sites running any version of the Fastcache by Host.it plugin up to and including 1.7.5 are affected. The issue is tied specifically to the plugin’s admin_action_update hook and the updateSettings() function, which is not protected by proper capability checks. Any site that has this plugin activated and at least a subscriber‑level account is at risk.

The CVSS score of 4.3 indicates moderate severity. The EPSS score is not published, so the likelihood of exploitation cannot be quantified, but the fact that the attack requires only authentication at the subscriber level suggests that the risk is non‑negligible if an attacker compromises a low‑privilege account. The vulnerability is not listed in the CISA KEV catalog, implying no confirmed exploitation at the time of this analysis. An attacker could exploit this by logging into the site with a subscriber account, navigating to the plugin’s settings, and modifying the rewrite rules, potentially causing service disruption or leaking cached content.