CVE-2025-27801
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-07-28

Last updated on: 2025-11-03

Assigner: SEC Consult Vulnerability Lab

Description
The Episerver Content Management System (CMS) by Optimizely was affected by multiple Stored Cross-Site Scripting (XSS) vulnerabilities. This allowed an authenticated attacker to execute malicious JavaScript code in the victim's browser. ContentReference properties, which could be used in the "Edit" section of the CMS, offered an upload functionality for documents. These documents could later be used as displayed content on the page. It was possible to upload SVG files that include malicious JavaScript code that would be executed if a user visited the direct URL of the preview image. Attackers needed at least the role "WebEditor" in order to exploit this issue. Affected products: Version 11.X: EPiServer.CMS.Core (<11.21.4) with EPiServer.CMS.UI (<11.37.5), Version 12.X: EPiServer.CMS.Core (<12.22.1) with EPiServer.CMS.UI (<11.37.3)
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Meta Information
Published
2025-07-28
Last Modified
2025-11-03
Generated
2026-05-07
AI Q&A
2025-07-28
EPSS Evaluated
2026-05-05
NVD
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
optimizely episerver.cms.core 12.0
optimizely episerver.cms.core 11.0
optimizely episerver.cms.ui 11.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
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.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability involves multiple Stored Cross-Site Scripting (XSS) issues in the Episerver Content Management System (CMS) by Optimizely. Authenticated attackers with at least the 'WebEditor' role could upload SVG files containing malicious JavaScript code via the document upload functionality in the CMS's Edit section. When a user visits the direct URL of the preview image, the malicious script executes in their browser.


How can this vulnerability impact me? :

The vulnerability allows an attacker with WebEditor privileges to execute malicious JavaScript in the browsers of users who view the uploaded SVG preview images. This can lead to unauthorized actions performed on behalf of the user, theft of sensitive information, session hijacking, or other malicious activities within the context of the victim's browser session.


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