CVE-2026-31281

CVE-2026-31281 is a high-severity vulnerability with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

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.

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 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-31281 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-31281?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-31281 have an EU (EUVD) identifier?
Yes. CVE-2026-31281 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21928.
When was CVE-2026-31281 published?
CVE-2026-31281 was published on 2026-04-13 and last updated on 2026-06-17.

References

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