CVE-2020-5809

MEDIUM

Umbraco CMS <= 8.9.1 - Authenticated Stored Cross-Site Scripting via TinyMCE Iframe Injection

Title source: llm
STIX 2.1

Description

A stored XSS vulnerability exists in Umbraco CMS <= 8.9.1 or current. An authenticated user can inject arbitrary JavaScript code into iframes when editing content using the TinyMCE rich-text editor, as TinyMCE is configured to allow iframes by default in Umbraco CMS.

References (1)

Core 1
Core References
Exploit, Third Party Advisory x_refsource_misc
https://www.tenable.com/security/research/tra-2020-59

Scores

CVSS v3 5.4
EPSS 0.0042
EPSS Percentile 62.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Details

CWE
CWE-79
Status published
Products (2)
nuget/UmbracoCms.Core 0NuGet
umbraco/umbraco_cms < 8.9.1
Published Dec 30, 2020
Tracked Since Feb 18, 2026