title: Nextcloud Server vulnerable to Self XSS when pasting HTML into Text app with Ctrl+Shift+V
description: Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Server and Nextcloud Enterprise Server, when a user is tricked into copy pasting HTML code without markup (Ctrl+Shift+V) the markup will actually render. Nextcloud Server and Nextcloud Enterprise Server versions 25.0.13, 26.0.8, and 27.1.3 contain a fix for this issue. As a workaround, disable app text.
problem types: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
affected:
{
vendor: nextcloud
product: security-advisories
versions:
version: >= 25.0.0, < 25.0.13, status: affected
version: >= 26.0.0, < 26.0.8, status: affected
version: >= 27.0.0, < 27.1.3, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 3.5
baseSeverity: LOW
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
version: 3.1
]