XSS in Jegstudio Gutenverse – WordPress Blocks, Page Builder & Site Editor

CVE-2026-19943

The Gutenverse – WordPress Blocks, Page Builder & Site Editor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'titleTag' Block Attribute in all versions up to, and including, 4.0.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The malicious titleTag value survives wp_kses_post on save because it is stored inside a block-comment delimiter and the live HTML is only synthesized at render time by do_blocks(), meaning the payload also fires in administrator and editor sessions during post preview.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (9.9th percentile) — read the EPSS interpretation.