CVE-2025-27802 – “Optimizely Episerver Stored Cross-Site Scripting (XSS) Vulnerability”

CVE ID : CVE-2025-27802

Published : July 28, 2025, 9:15 a.m. | 2 hours, 3 minutes ago

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.

RTE properties (text fields), which could be used in the “Edit” section of the CMS,
allowed the input of arbitrary text. It was possible to input malicious JavaScript
code in these properties that would be executed if a user visits the previewed
page. Attackers needed at least the role “WebEditor” in order to exploit this issue.

Affected products: Version 11.X: EPiServer.CMS.Core (
Severity: 4.8 | MEDIUM

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