CVE-2026-101935: Echo Knowledge Base reflected cross-site scripting (XSS) vulnerability
medium 6.1 published 2026-10-28 · updated 2026-10-29
- Affected versions
- 17.214.0 and older
- Fixed in
- 17.311.0 *
- Latest version
- 17.311.1
- Severity
- Medium · CVSS 6.1
- Active installs
- 10,000+
- Type
- Reflected cross-site scripting (XSS)
* The source does not name a fixed version; this is the first wordpress.org release after the last affected version.
What an attacker needs
- Access: None. No account or login is needed.
- Interaction: It also needs someone on the site (often an admin) to click a link, open a page or submit a form the attacker prepared.
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
What to do now
- Update Echo Knowledge Base to 17.311.0 or newer (the latest is 17.311.1): Dashboard → Updates, or Plugins → “update now”.
- If you cannot update right away, deactivate it until you can.
- Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
- Not sure which version you run? Check your version against every known Echo Knowledge Base issue.
With WP-CLI:
wp plugin get echo-knowledge-base --field=version. - If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.
The advisory
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.
References
- NVD CVE-2026-101935 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
- Plugin source plugins.trac.wordpress.org
Related
Ran an affected version? Check your site for signs of a hack
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Where this data comes from
- CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
- Versions and install counts: wordpress.org/plugins/echo-knowledge-base (Plugins API), fetched 2026-11-04.
- The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.