CS-Cart and Multi-Vendor 4.21: smarter product lists, structured data and CommerceML

CS-Cart released version 4.21.1 of CS-Cart and Multi-Vendor on August 25, 2026, followed by the 4.21.2 maintenance release on September 22, 2026. The new line focuses on three areas: smoother shopping in the Nova theme, a better description of your store for search engines and AI assistants, and more flexible marketplace management. On top of that comes a new add-on for exchanging data with external systems and cost control for paid map services. Below we go through the changes that will matter most in your daily work with the store.

Smarter product lists in the Nova theme

Customers can now change the product quantity directly on the product page, on the category page and in product blocks, without going to the cart. It is a small change that saves a lot of clicks when someone buys several items of the same product. The second improvement concerns images: when the cursor hovers over a product in a list, its next image can appear, so shoppers judge the product faster without opening its page.

Structured data for Google and AI assistants

In version 4.21.1 the SEO add-on publishes BreadcrumbList markup, the description of the navigation path that search engines use to show breadcrumbs in results. The panel also gained an Organization markup editor, where you add the company description, phone, email and links to its profiles on other services, while the store adds its name and logo on its own. This information helps Google and AI assistants recognize who is behind the store.

If you want to go further, our JSON-LD and GEO structured data add-on fills the store with complete Schema.org markup on every page, including product data taken from CS-Cart features and a return policy that meets Google requirements.

New CommerceML add-on

The package now includes a CommerceML add-on. It imports products from systems that support this data exchange standard and exports orders to them. It is useful when the store has to work with an external sales or warehouse system that speaks CommerceML.

Maps without billing surprises

The Maps and geolocation add-on received cost controls for paid map APIs. The store sends fewer unnecessary location requests, and the panel suggests how to set up billing with the map provider. In Multi-Vendor the same safeguards were added to the Vendor locations add-on, which is still in beta.

New handling of pickup points

The Pickup from store shipping method uses a new mechanism for storing and displaying pickup points. Addresses share one format, and the list of points is cached, so the store does not have to build it from scratch every time. The vendor says this architecture will be the basis for future carrier integrations.

Multi-Vendor: promotions for selected vendors

Catalog promotions gained a Vendors condition. A marketplace operator can prepare a discount that covers only the products of chosen vendors, without picking their products one by one.

Security and other changes

Release 4.21.2 is above all a set of security fixes, so we recommend the update to every store on the 4.21 line. Other changes from both releases worth knowing:

• password fields and similar fields in the panel are hidden by default, and their content can be revealed with a toggle,
• data saved by the core in the storage_data mechanism can have an expiration time, which is handy for add-on developers,
• version 4.21.2 fixes a PHP error shown on Form Builder form pages with PHP 8.1 and newer.

CS-Cart and Multi-Vendor 4.21 run on PHP from 7.4 to 8.3. Full server requirements are on the System requirements page.

Upgrading to 4.21

Any license owner with active access to new versions can run the upgrade. If your store has custom modifications or third-party add-ons, we will gladly do it for you: first on a copy of the store, and only after testing on the live version. Contact us and we will prepare a quote.