CVE-2026-31281: Totara LMS v19.1.5 and before is vulnerable to HTML Injection. An attacker can inject malicious HTML code in a message and send it to all the users in...

Description

Totara LMS v19.1.5 and before is vulnerable to HTML Injection. An attacker can inject malicious HTML code in a message and send it to all the users in the application, resulting in executing the code and may lead to session hijacking and executing commands on the victim's browser. NOTE: The supplier states that the product name is Totara Learning and that the functionality referenced is the in app messaging client. They note that the in app messaging client only has the ability to embed a specific allowed list of HTML tags commonly used for text enhancement, which includes italic, bold, underline, strong, etc. Last, they state that the in app messaging client cannot embed <script>, <style>, <iframe>, <object>, <embed>, <form>, <input>, <button>, <svg>, <math>, etc., and any attempt to embed tags or attributes outside of the allowed list (including onerror, onaction, etc.) is sanitized via DOMPurify.

Metrics

CVSS 3.1

8/10

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

EPSS Probability

0.30%

21.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Apr 13, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-31281?

Totara LMS v19.1.5 and before is vulnerable to HTML Injection. An attacker can inject malicious HTML code in a message and send it to all the users in the application, resulting in executing the code and may lead to session hijacking and executing commands on the victim's browser. NOTE: The supplier states that the product name is Totara Learning and that the functionality referenced is the in app messaging client. They note that the in app messaging client only has the ability to embed a specific allowed list of HTML tags commonly used for text enhancement, which includes italic, bold, underline, strong, etc. Last, they state that the in app messaging client cannot embed <script>, <style>, <iframe>, <object>, <embed>, <form>, <input>, <button>, <svg>, <math>, etc., and any attempt to embed tags or attributes outside of the allowed list (including onerror, onaction, etc.) is sanitized via DOMPurify.

How severe is CVE-2026-31281?

CVE-2026-31281 has a CVSS score of 8/10 (HIGH severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2026-31281?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.