# CVE-2025-27801: Stored Cross-Site Scripting in Episerver Content Management System (CMS) Media Selection Preview

> CVE-2025-27801: Stored Cross-Site Scripting in Episerver Content Management System (CMS) Media Selection Preview. CVSS 4.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2025-27801
Last updated: 2026-06-17T09:04:14Z

- Published: 2025-07-28 08:40 UTC · Updated: 2026-06-17 09:04 UTC · Assigner: SEC-VLab
- CVSS: 4.8 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
- EPSS: 0.36%, 30th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-79

## 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)

## Affected vendors and products

- Optimizely: Episerver Content Management System (CMS)

## Tracked companies

- [Optimizely](https://rewindex.com/company/optimizely.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-27801)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-27801)
- [https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4\#](https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4#)
- [https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1\#](https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1#)
- [https://r.sec-consult.com/optimizely](https://r.sec-consult.com/optimizely)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-27801 · Markdown: https://rewindex.com/cve/CVE-2025-27801.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-27801 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:15:38.894Z