CVE catalog
CVE-2026-42857
Open edX Platform enables the authoring and delivery of online learning at any scale. The HTML sanitizer clean_thread_html_body() used for discussion notification emails fails to remove <style> tags f
- Severity
- Medium · CVSS 4.6
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.18% · Oct 25, 2026
Open edX Platform enables the authoring and delivery of online learning at any scale. The HTML sanitizer clean_thread_html_body() used for discussion notification emails fails to remove <style> tags from user-generated discussion post content. This content is rendered with Django's |safe template filter in email notification templates, allowing any enrolled student to inject arbitrary CSS into email notifications sent to other users. This enables email tracking (IP address disclosure), content spoofing, and phishing attacks. This vulnerability is fixed with commit cddc25cd791bb78f76833896e4778f668861df12.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | openedx | Not reported | 2026-04-24 | fixed |
| Cpe | openedx | Not reported | 2026-04-24 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | openedx | cpe | Not reported | 2026-04-24 | Not reported | Not reported | Not reported |
| Cpe | openedx | cpe | Not reported | 2026-04-24 | Not reported | NVD-CVE-2026-42857 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed: