Vulnerability · Published Jul 28, 2025 · Assigned by SEC-VLab

CVE-2025-27800Stored Cross-Site Scripting in Episerver Content Management System (CMS) Admin Dashboard

Medium 4.8

In plain English

A medium-severity cross-site scripting in Episerver Content Management System (CMS) from Optimizely. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).

Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.4%top 65.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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)

Affected products (as reported)

VendorProductVersions
Optimizely Episerver Content Management System (CMS) 11.x – before 11.21.412.x – before 12.22.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

References