CVE-2025-27800

medium

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)

References

https://r.sec-consult.com/optimizely

https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1#

https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4#

Details

Source: Mitre, NVD

Published: 2025-07-28

Updated: 2025-07-29

Risk Information

CVSS v2

Base Score: 4.7

Vector: CVSS2#AV:N/AC:L/Au:M/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 4.8

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 4.8

Vector: 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

Severity: Medium

EPSS

EPSS: 0.00027