The EWWW Image Optimizer WordPress plugin before 8.8.0 does not confine a WebP-derivative file migration routine to the current site's own uploads directory, letting an attacker with Administrator-level access rename or delete existing WebP-derivative image files outside that scope, including, on a multisite network, files belonging to a different site they have no access to.

The EWWW Image Optimizer WordPress plugin before 8.8.0 does not confine a WebP-derivative file migration routine to the current site's own uploads directory, letting an attacker with Administrator-level access rename or delete existing WebP-derivative image files outside that scope, including, on a multisite network, files belonging to a different site they have no access to.