6.1
MEDIUM CVSS 3.1
CVE-2026-88963
Tutor LMS <= 4.0.8 - Authenticated (Subscriber+) Reflected DOM-Based Cross-Site Scripting via 'redirect_url' Parameter
Description

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.

INFO

Published Date :

Oct. 16, 2026, 6:17 a.m.

Last Modified :

Oct. 16, 2026, 6:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-88963 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Themeum tutor_lms
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
Solution
Update the Tutor LMS plugin to version 4.0.9 or later to fix DOM-based XSS.
  • Update Tutor LMS plugin to version 4.0.9 or later.
  • Ensure the 'redirect_url' parameter is properly validated.
  • Review Topbar component's back button handler.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-88963 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-88963 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-88963 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-88963 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 16, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/88xxx/CVE-2026-88963.json">CVE-2026-88963</a>
    Added Reference https://plugins.trac.wordpress.org/changeset/3700174/tutor/trunk/assets/js/tutor-order-details.js
    Added Reference https://plugins.trac.wordpress.org/changeset?reponame=&new=3700174%40tutor%2Ftags%2F4.0.9&old=3690454%40tutor%2Ftags%2F4.0.8
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/f39a9570-a352-45f3-8644-2de2c1c709d2?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.