The Otter Blocks WordPress plugin before 3.2.8 does not correctly bound a pattern it uses to rewrite its dynamic-content tokens while rendering blocks, so the pattern can consume the quote that closes an HTML attribute and pull adjacent unescaped data into the markup as new attributes. This allows unauthenticated users to achieve stored Cross-Site Scripting that executes in the browser of any visitor who views an affected page, including a logged-in administrator.

The Otter Blocks WordPress plugin before 3.2.8 does not enforce its block visibility conditions when a published post is rendered through the WordPress REST API, allowing unauthenticated users to read block content that the site owner restricted to specific roles, logged-in users, the post author, categories or tags, or (on the Pro tier) Stripe purchasers.

The Otter Blocks WordPress plugin before 3.2.8 does not properly sanitize and escape user-supplied block styling values before writing them into an inline stylesheet, allowing users with contributor-level access and above to inject arbitrary web scripts that execute when any visitor, including administrators, views the affected post.

The Otter Blocks WordPress plugin before 3.2.8 does not correctly determine whether a post is publicly readable before returning its data through a REST API endpoint, treating any post with the published status as public, allowing unauthenticated users to read manual excerpts of password-protected posts, the content and titles of non-public post types, and, on WooCommerce sites, coupon codes and their descriptions.

The Otter Blocks WordPress plugin before 3.2.3 does not validate that a user-supplied return URL belongs to the site before using it to build the return destination of a Stripe Checkout session, allowing unauthenticated attackers to redirect victims who complete or cancel checkout to an arbitrary external URL.

The Otter Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 3.2.6 via the 'otterformwidgetfilter' parameter. This makes it possible for authenticated attackers, with subscriber-level access and above, to extract the email addresses of the five most recent form submitters, their submission dates, and the site's total form submission count. The widget is registered whenever the themeisleblocksformemails option is non-empty — the normal state after any Form block has been saved — meaning the exposure is active on any standard site using the plugin's form feature.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Themeisle Otter Blocks PRO.This issue affects Otter Blocks PRO: from n/a through 2.6.11.