CVE-2025-27802

MEDIUM EPSS 24.4%

Published Jul 28, 202511mo ago · Modified Jun 17, 20262w ago

4.8 CVSS 4.0

Medium

Published Jul 28, 2025 11mo ago

Last Modified Jun 17, 2026 2w 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 (<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)

CVSS Details

Base Score

4.8

Exploitability

—

Impact

—

Vector string

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector Network

Attack Complexity Low

Privileges Required High

User Interaction P

Scope X

Threat Intelligence

EPSS Exploit Probability

24.4% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

References 4

seclists.org http://seclists.org/fulldisclosure/2025/Aug/18
api.nuget.optimizely.com https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4#
api.nuget.optimizely.com https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1#
r.sec-consult.com https://r.sec-consult.com/optimizely

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.