CVE-2026-110018

The aBlocks – Gutenberg Blocks, User Dashboard Builder, Popup Builder, Form Builder & Animation Builder plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 2.17.0 via the /ablocks/v1/form-builder/registration REST endpoint. The vulnerability exists because the endpoint is registered with permission callback => return true and the register() handler reads roleSlug directly from attacker-controlled block attributes in post content without ever verifying that the block's formType is registration — a condition that RegistrationFormSanitizer::verify() imposes only at save-time, meaning a Contributor can preserve an arbitrary roleSlug by saving a block with formType='login' and then triggering the endpoint via a valid wp rest nonce and post-ownership check. This makes it possible for authenticated attackers, with Contributor-level access and above, to escalate their WordPress role to Editor or any other non-administrator role and receive a fully authenticated session at the elevated privilege level via WP User::set role() and wp set auth cookie(). Escalation is bounded below administrator-tier roles because is safe registration role() rejects any role holding manage options, edit users, delete users, create users, promote users, or edit theme options, meaning the highest practically reachable role on a standard WordPress installation is Editor.