CVE-2026-42857

Published: Mag 11, 2026 Last Modified: Mag 11, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 4,6
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: required
Scope: unchanged
Confidentiality: low
Integrity: low
Availability: none

Description

AI Translation Available

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.

79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Confidentiality Integrity Availability
Potential Impacts:
Bypass Protection Mechanism Read Application Data Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: AI/ML, Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
https://github.com/openedx/openedx-platform/commit/cddc25cd…
https://github.com/openedx/openedx-platform/commit/cddc25cd791bb78f76833896e477…
https://github.com/openedx/openedx-platform/security/adviso…
https://github.com/openedx/openedx-platform/security/advisories/GHSA-4xv3-5j4x-…