EnumGuard is a focused WordPress plugin that stops attackers from confirming that a username or user ID exists. WordPress still prints those signals by default; EnumGuard closes the usual paths without hiding display names on posts.

Under Settings EnumGuard you get three tabs:

Protections — overview of which discovery paths are closed
Settings — toggles and custom login / reset messages
About — plugin info

Protections covered:

Author ID queries (?author=1) that would otherwise redirect to the author archive
Author archives and their feeds
Author archive links printed in HTML
author-{id} / author-{nicename} body, post, and comment CSS classes
Core users sitemap (/wp-sitemap-users-1.xml)
Unauthenticated /wp-json/wp/v2/users (including ?rest_route=)
REST _embed author payloads and author link headers
Login error messages that distinguish “bad username” from “bad password”
Lost-password responses (same confirmation whether the account exists)
oEmbed author_url / author_name
XML-RPC user-listing methods, with an optional full XML-RPC disable
Author sitemaps and author archive URLs from Yoast, Rank Math, and The SEO Framework

Recommended protections ship enabled. Gutenberg still reaches the users REST API for logged-in editors. Display names stay visible. Login and reset protections also cover WooCommerce forms when WooCommerce is active. XML-RPC can be turned off completely if you do not need Jetpack, pingbacks, or the WordPress mobile app.