CVE-2025-27801
Optimizely Episerver Stored Cross-Site Scripting (XSS) Vulnerability
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. ContentReference properties, which could be used in the "Edit" section of the CMS, offered an upload functionality for documents. These documents could later be used as displayed content on the page. It was possible to upload SVG files that include malicious JavaScript code that would be executed if a user visited the direct URL of the preview image. 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)
INFO
Published Date :
July 28, 2025, 9:15 a.m.
Last Modified :
July 29, 2025, 2:14 p.m.
Remotely Exploit :
Yes !
Source :
551230f0-3615-47bd-b7cc-93e92e730bbf
Affected Products
The following products are affected by CVE-2025-27801
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 551230f0-3615-47bd-b7cc-93e92e730bbf | ||||
| CVSS 4.0 | MEDIUM | 551230f0-3615-47bd-b7cc-93e92e730bbf |
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-27801.
| URL | Resource |
|---|---|
| https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4# | |
| https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1# | |
| https://r.sec-consult.com/optimizely |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-27801 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-27801
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-27801 vulnerability anywhere in the article.
-
seclists.org
SEC Consult SA-20250728-0 :: Stored Cross-Site-Scripting in Optimizely Episerver CMS
Full Disclosure mailing list archives SEC Consult SA-20250728-0 :: Stored Cross-Site-Scripting in Optimizely Episerver CMS From: SEC Consult Vulnerability Lab via Fulldisclosure <fulldisclosure () sec ... Read more
The following table lists the changes that have been made to the
CVE-2025-27801 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 551230f0-3615-47bd-b7cc-93e92e730bbf
Jul. 29, 2025
Action Type Old Value New Value Added Reference https://api.nuget.optimizely.com/packages/episerver.cms.core/11.21.4# Added Reference https://api.nuget.optimizely.com/packages/episerver.cms.core/12.22.1# Added Reference https://r.sec-consult.com/optimizely Removed Reference https://support.optimizely.com/hc/en-us/articles/30886353301645-2025-Optimizely-CMS-11-PaaS-release-notes#h_01K09MR1SZS4FEAPD4478GQ0FR Removed Reference https://support.optimizely.com/hc/en-us/articles/37757063222029-2024-Optimizely-CMS-12-PaaS-release-notes#h_01JN4AZV48WKNADH3KWC2GYDS5 -
CVE Modified by 551230f0-3615-47bd-b7cc-93e92e730bbf
Jul. 28, 2025
Action Type Old Value New Value Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:A/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 Removed CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:A/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 -
New CVE Received by 551230f0-3615-47bd-b7cc-93e92e730bbf
Jul. 28, 2025
Action Type Old Value New Value Added 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. ContentReference properties, which could be used in the "Edit" section of the CMS, offered an upload functionality for documents. These documents could later be used as displayed content on the page. It was possible to upload SVG files that include malicious JavaScript code that would be executed if a user visited the direct URL of the preview image. 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) Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:A/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 Added CVSS V3.1 AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://support.optimizely.com/hc/en-us/articles/30886353301645-2025-Optimizely-CMS-11-PaaS-release-notes#h_01K09MR1SZS4FEAPD4478GQ0FR Added Reference https://support.optimizely.com/hc/en-us/articles/37757063222029-2024-Optimizely-CMS-12-PaaS-release-notes#h_01JN4AZV48WKNADH3KWC2GYDS5