Back

MEDIUM

Open edX Platform: Stored CSS Injection in Email Digest Notifications via Unsanitized Thread Title (incomplete patch of CVE-2026-42857)

Published Sep 18, 2026

Description

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.

Affected products

Remediation

No remediation recorded yet.

References (7)

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED
Assigner GitHub_M
Published Sep 18, 2026
Updated Sep 22, 2026
Reserved Sep 3, 2026

CISA Vulnrichment

Updated Sep 22, 2026

NVD

Status Received
Modified Sep 18, 2026

Red Hat

No data

ENISA EUVD

Assigner GitHub_M
Published Sep 18, 2026
Updated Sep 22, 2026

GitHub

No data