CVE-2026-88963: Tutor LMS DOM-based cross-site scripting (XSS) vulnerability
medium 6.1 published 2026-10-16
- Affected versions
- 4.0.8 and older
- Fixed in
- 4.0.9 *
- Latest version
- 4.2.0
- Severity
- Medium · CVSS 6.1
- Active installs
- 100,000+
- Type
- DOM-based 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 Tutor LMS to 4.0.9 or newer (the latest is 4.2.0): 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 Tutor LMS issue.
With WP-CLI:
wp plugin get tutor --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 Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to DOM-Based Cross-Site Scripting via the 'redirect_url' parameter in versions up to, and including, 4.0.8 This is due to insufficient input validation in the Topbar component's back button handler. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute in the victim's browser whenever the victim accesses a page that includes the malicious payload.
References
- NVD CVE-2026-88963 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
Related
Ran an affected version? Check your site for signs of a hack
The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.
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/tutor (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.