CVE-2025-4420 Cross-site scripting in Vayu Blocks – Website Builder for the Block Editor
Authenticated attackers can inject arbitrary scripts via the containerWidth parameter, leading to stored XSS execution on victim pages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-4420?
CVE-2025-4420 is a medium-severity cross-site scripting vulnerability in themehunk Vayu Blocks – Website Builder for the Block Editor, published on 3 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Vayu Blocks – Gutenberg Blocks for WordPress & WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘containerWidth’ parameter in all versions up to, and including, 1.3.1 due to a missing capability check on the vayu_blocks_option_panel_callback() function and insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Weakness: CWE-79
Which versions are affected by CVE-2025-4420?
How do I fix CVE-2025-4420?
No fix has been published for CVE-2025-4420 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-4420 being exploited?
There is no known exploitation of CVE-2025-4420 in the wild and no public exploit code.
Sources
Also known as GHSA-g47q-4gcv-4qvr.