CVE-2026-6397 MEDIUM

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

Vendor Cvmh
Product Sticky
Weakness CWE-79 · XSS
Published May 20, 2026
Last update May 20, 2026

CVSS base score

6.4/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

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.

Explanation of Vulnerability in Simple Terms

02Summary

Sticky versions 2.5.6 and earlier contain a cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious scripts. The vulnerability has a changed scope, meaning the impact can extend beyond the vulnerable component itself. Low-privileged users can exploit this without user interaction to compromise site integrity and access sensitive information.

What an attacker can do

03Attacker Capabilities

Inject malicious scripts that execute in other users' browsers and affect site functionality.

Potential impact on your site

04Site Impact

Authenticated users can inject scripts affecting other visitors and site operations; data theft or defacement possible.

Conditions required to exploit

05Prerequisites

Attacker must have a low-privilege account on the site; no user interaction required.

Key dates

06Disclosure timeline

May 20, 2026 CVE published
May 20, 2026 Record updated

Related vulnerabilities

08Related CVE