CVE-2026-0894 Cross-site scripting in Content Blocks (Custom Post Widget)
Authenticated attackers can inject arbitrary scripts via the content_block shortcode, leading to code execution when users view affected 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-2026-0894?
CVE-2026-0894 is a medium-severity cross-site scripting vulnerability in vanderwijk Content Blocks (Custom Post Widget), published on 18 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's content_block shortcode in all versions up to, and including, 3.3.9 due to insufficient input sanitization and output escaping on user supplied values consumed from user-created content blocks. 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-0894?
How do I fix CVE-2026-0894?
No fix has been published for CVE-2026-0894 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-2026-0894 being exploited?
There is no known exploitation of CVE-2026-0894 in the wild and no public exploit code.
Sources
Also known as GHSA-23v6-h45q-rxch.