CVE-2025-66512 MEDIUM

CVE-2025-66512: Nextcloud Server vulnerable to XSS in SVG images when opened outside of Nextcloud

Vendor Nextcloud
Product security-advisories
Weakness CWE-80 · XSS · basic
Published December 5, 2025
Last update December 5, 2025
View on NVD All CVEs

CVSS base score

5.4/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server and Server Enterprise prior to 31.0.12 and 32.0.3, a missing sanitization allowed malicious users to circumvent the content security policy when a malicious user manages to trick a user it viewing an uploaded SVG outside of the Nextcloud Servers web page.

Key dates

02Disclosure timeline

December 5, 2025 CVE published
December 5, 2025 Record updated