CVE-2026-88963

Tutor LMS <= 4.0.8 - Authenticated (Subscriber+) Reflected DOM-Based Cross-Site Scripting via 'redirect_url' Parameter

2026-10-15 16:58
Sevada797

Strategic Overview

Status
Patched in 4.0.9
Affected Plugin
Tutor LMS – eLearning and online course solution
Affected Version
<= 4.0.8
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-88963
View all Tutor LMS – eLearning and online course solution vulnerabilities

At a glance

CVE-2026-88963 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Tutor LMS WordPress plugin, affecting versions <= 4.0.8. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.0.9; sites on affected versions should update now. Disclosed October 2026, reported by Sevada797.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Tutor LMS <= 4.0.8 carries this weakness at redirect_url, and reaching it takes an account at Subscriber level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Tutor LMS the fix is 4.0.9: builds <= 4.0.8 are affected, anything from 4.0.9 onward is not.

Remediation

Update to version 4.0.9, or a newer patched version

How does WordSec protect against this?

An attacker needs Subscriber access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Tutor LMS 4.0.9 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-88963https://www.wordfence.com/threat-intel/vulnerabilities/id/f39a9570-a352-45f3-8644-2de2c1c709d2https://nvd.nist.gov/vuln/detail/CVE-2026-88963

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C