openedx Open edX Platform up to release/ulmo.3/ulmo.3 Email utils.py add_additional_attributes_to_notifications post_title cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in openedx Open edX Platform up to release/ulmo.3/ulmo.3. Impacted is the function add_additional_attributes_to_notifications of the file openedx/core/djangoapps/notifications/email/utils.py of the component Email. Executing a manipulation of the argument post_title can lead to cross site scripting. This vulnerability is registered as CVE-2026-85271. It is possible to launch the attack remotely. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in openedx Open edX Platform up to release/ulmo.3/ulmo.3 and classified as problematic. This vulnerability affects the function add_additional_attributes_to_notifications of the file openedx/core/djangoapps/notifications/email/utils.py of the component Email. The manipulation of the argument post_title with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

Open edX Platform enables the authoring and delivery of online learning at any scale. From Redwood until Ulmo and Verawood.1, the add_additional_attributes_to_notifications function in openedx/core/djangoapps/notifications/email/utils.py assigns notification content without sanitizing discussion-title values produced by get_notification_content in openedx/core/djangoapps/notifications/base_notification.py. An enrolled student can place CSS-capable markup in the post_title value supplied by lms/djangoapps/discussion/rest_api/discussions_notifications.py. Digest and batched-email rendering then passes that value through openedx/core/djangoapps/notifications/templates/notifications/digest_content.html as safe HTML, allowing email-open tracking and content spoofing or phishing when another learner opens a CSS-rendering client. The immediate-email path is not affected because it strips title markup and renders a separately sanitized body. This issue is fixed in Ulmo and Verawood.1.

The advisory is available at github.com. This vulnerability was named CVE-2026-85271 since 09/03/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

Upgrading to version release or ulmo.4 eliminates this vulnerability.

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Productinfo

Vendor

• openedx

Name

• Open edX Platform

Version

• release
• ulmo.0
• ulmo.1
• ulmo.2
• ulmo.3

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CPE 2.2info

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