CVE-2026-1300 Responsive Header Plugin <= 1.0 - Authenticated (Administrator+) Stored Cross-Site Scripting via Settings Parameters
Administrators can inject arbitrary scripts via settings parameters in the Responsive Header WordPress plugin, affecting multi-site or restricted HTML installations.
- 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-2026-1300?
CVE-2026-1300 is a medium-severity cross-site scripting vulnerability in mehtevas Responsive Header Plugin, published on 24 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
The Responsive Header plugin for WordPress is vulnerable to Stored Cross-Site Scripting via multiple plugin settings parameters in all versions up to, and including, 1.0 due to insufficient input sanitization and output escaping. 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 only affects multi-site installations and installations where unfiltered_html has been disabled.
Weakness: CWE-79
Which versions are affected by CVE-2026-1300?
How do I fix CVE-2026-1300?
No fix has been published for CVE-2026-1300 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-2026-1300 being exploited?
There is no known exploitation of CVE-2026-1300 in the wild and no public exploit code.
Sources
Also known as GHSA-6qhv-2vf7-29hf.