Open edX Platform: Stored CSS Injection in Email Digest Notifications via Unsanitized Thread Title (incomplete patch of CVE-2026-42857)
Published Sep 18, 2026
6.1
MEDIUMCVSS 3.1
EPSS 0.35%
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
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Affected
- ≥ release/redwood.1, < release/ulmo.4
Default status is the baseline for the product. Each version can override it (patched versions can be marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| Openedx | Openedx-Platform | unknown | Affected
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (7)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-83443 Advisory
- https://github.com/openedx/openedx-platform/commit/2af03d21b4142e53e375c7f3699b313e92ec5121 x_refsource_MISC
- https://github.com/openedx/openedx-platform/commit/52f2b3bb3e6fac2601c29e8f926c81498d20bb0b x_refsource_MISC
- https://github.com/openedx/openedx-platform/commit/5eae6e51a8797cd3b87cc132f5de73d52561c4d7 x_refsource_MISC
- https://github.com/openedx/openedx-platform/releases/tag/release/ulmo.4 x_refsource_MISC
- https://github.com/openedx/openedx-platform/releases/tag/release/verawood.1 x_refsource_MISC
- https://github.com/openedx/openedx-platform/security/advisories/GHSA-rv5w-f4r5-h77g x_refsource_CONFIRM
Change history (0)
No recorded changes yet.
CVE.org / MITRE
CISA Vulnrichment
Red Hat
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GitHub
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