CVE-2025-27800

MEDIUM EPSS 28.1%

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. The Admin dashboard offered the functionality to add gadgets to the dashboard. This included the "Notes" gadget. An authenticated attacker with the corresponding access rights (such as "WebAdmin") that was impersonating the victim could insert malicious JavaScript code in these notes that would be executed if the victim visited the dashboard. 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:N/VA:N/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

28.1% 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.