CVE-2026-101935: XSS (CVSS 6.1)

Description

The Echo Knowledge Base – Documentation, FAQs, Chat & Smart Search plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'new_kb_config' parameter (specifically the article-mobile-break-point-v2 key, among other config keys interpolated into the <style> element) in versions up to, and including, 17.214.0 This is due to insufficient input sanitization and output escaping in EPKB_Frontend_Editor::fe_preview_config() and EPKB_Articles_Setup: on every knowledge base article page view, when the request supplies epkb_fe_reload_mode=on, an attacker-controlled JSON blob is merged over the stored KB configuration and several values are concatenated directly into a stylesheet emitted inside a literal <style> element without escaping (minify_css() does not strip <, > or /). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user (with Editor-level access or above, holding the manage_categories capability, or an Administrator) into performing an action such as clicking on a specially crafted link.

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CVSS v3.1 Score

6.1

MEDIUM

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

EPSS — Exploit Prediction

0.0025

Probability of exploitation

0.17%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/admin/editor/class-epkb-frontend-editor.php#L1072 https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/admin/editor/class-epkb-frontend-editor.php#L848 https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/class-epkb-utilities.php#L836 https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/features/articles/class-epkb-articles-setup.php#L131 https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/features/articles/class-epkb-articles-setup.php#L319 https://plugins.trac.wordpress.org/browser/echo-knowledge-base/tags/17.214.0/includes/features/layouts/class-epkb-layouts-setup.php#L45 https://plugins.trac.wordpress.org/changeset/3727663/echo-knowledge-base/trunk/includes/admin/editor/class-epkb-frontend-editor.php https://plugins.trac.wordpress.org/changeset?reponame=&new=3727647%40echo-knowledge-base%2Ftags%2F17.311.0&old=3672811%40echo-knowledge-base%2Ftags%2F17.214.0 https://www.wordfence.com/threat-intel/vulnerabilities/id/3bfab9cf-4ccb-45fc-83ce-b5250f0f6482?source=cve

Frequently Asked Questions

What is CVE-2026-101935? +

The Echo Knowledge Base – Documentation, FAQs, Chat & Smart Search plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'new_kb_config' parameter (specifically the article-mobile-break-point-v2 key, among other config keys interpolated into the <style> element) in versions up to, and including, 17.214.0 This is due to insufficient input sanitization and output escaping in EPKB_Frontend_Editor::fe_preview_config() and EPKB_Articles_Setup: on every knowledge base article page view, when the request supplies epkb_fe_reload_mode=on, an attacker-controlled JSON blob is merged over the stored KB configuration and several values are concatenated directly into a stylesheet emitted inside a literal <style> element without escaping (minify_css() does not strip <, > or /). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user (with Editor-level access or above, holding the manage_categories capability, or an Administrator) into performing an action such as clicking on a specially crafted link. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-101935? +

CVE-2026-101935 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0025, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-101935? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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