CVE-2026-6397 Sticky <= 2.5.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'readmoretext' Shortcode Attribute
Authenticated attackers with Contributor access can inject arbitrary scripts via the readmoretext shortcode attribute, leading to stored XSS.
- 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-2026-6397?
CVE-2026-6397 is a medium-severity cross-site scripting vulnerability in cvmh Sticky, published on 20 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Sticky plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `cvmh-sticky` shortcode `readmoretext` attribute in versions up to and including 2.5.6. This is due to insufficient input sanitization and output escaping in the `cvmh_sticky_front_render()` function — the `readmoretext` attribute value is passed through `apply_filters()` and directly concatenated into the HTML output without any escaping function such as `esc_html()`. 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 a page containing the injected shortcode.
Weakness: CWE-79
Which versions are affected by CVE-2026-6397?
How do I fix CVE-2026-6397?
No fix has been published for CVE-2026-6397 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-2026-6397 being exploited?
There is no known exploitation of CVE-2026-6397 in the wild and no public exploit code.
Sources
Also known as GHSA-c2q9-qp4m-w7vm.