CVE-2026-2121 Cross-site scripting in Weaver Show Posts
Administrators can inject scripts via widget settings in multisite environments, affecting WordPress users with Weaver Show Posts.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-2121?
CVE-2026-2121 is a medium-severity cross-site scripting vulnerability in wpweaver Weaver Show Posts, published on 21 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
The Weaver Show Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'add_class' parameter in all versions up to, and including, 1.8.1. This is due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This primarily affects multisite installations where Administrators do not have the unfiltered_html capability.
Weakness: CWE-79
Which versions are affected by CVE-2026-2121?
How do I fix CVE-2026-2121?
No fix has been published for CVE-2026-2121 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-2026-2121 being exploited?
There is no known exploitation of CVE-2026-2121 in the wild and no public exploit code.
Sources
Also known as GHSA-qf9c-wfj4-w8fw.