XSS in Cvmh Sticky
CVE-2026-6397
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (24.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Cvmh Sticky — versions 0
Weakness classification (CWE)
References
- plugins.trac.wordpress.org/browser/sticky/tags/2.5.6/includes/functions.php
- plugins.trac.wordpress.org/browser/sticky/tags/2.5.6/includes/shortcode.php
- plugins.trac.wordpress.org/browser/sticky/trunk/includes/functions.php
- plugins.trac.wordpress.org/browser/sticky/trunk/includes/shortcode.php
- www.wordfence.com/threat-intel/vulnerabilities/id/135783c5-8175-4775-a013-f1e2b…
Frequently asked questions
- What is CVE-2026-6397?
- CVE-2026-6397 is a medium-severity vulnerability in Cvmh Sticky, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-05-20.
- How severe is CVE-2026-6397?
- Medium severity. CVSS v3 base score is 6.4 out of 10.