CVE-2026-8351 Cross-site scripting in RTMKit
Authenticated attackers with contributor access can inject arbitrary scripts via the Advanced Heading widget, leading to stored XSS execution on victim 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-2026-8351?
CVE-2026-8351 is a medium-severity cross-site scripting vulnerability in rometheme RTMKit, published on 3 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The RTMKit plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Advanced Heading widget's 'Background Text' parameter in versions up to, and including, 2.0.7 This is due to insufficient output escaping on the 'background_text_heading' setting in the render() function, which concatenates the value directly into an HTML attribute without applying esc_attr(). 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-2026-8351?
How do I fix CVE-2026-8351?
No fix has been published for CVE-2026-8351 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-2026-8351 being exploited?
There is no known exploitation of CVE-2026-8351 in the wild and no public exploit code.
Sources
Also known as GHSA-cvjh-fmg7-m8wm.