CVE-2026-19943 Gutenverse <= 4.0.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'titleTag' Block Attribute
Authenticated contributors can inject malicious scripts via the titleTag attribute, leading to script execution in admin sessions.
- 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-2026-19943?
CVE-2026-19943 is a medium-severity cross-site scripting vulnerability in jegstudio Gutenverse – WordPress Blocks, Page Builder & Site Editor, published on 25 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-19943?
How do I fix CVE-2026-19943?
No fix has been published for CVE-2026-19943 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-2026-19943 being exploited?
There is no known exploitation of CVE-2026-19943 in the wild and no public exploit code.
Sources
Also known as GHSA-548f-rjq8-x8r3.