CVE-2025-66512

Nextcloud Server vulnerable to XSS in SVG images when opened outside of Nextcloud

Published Dec 5, 2025 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Weaknesses CWE-79
CPEs cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
Type Values Removed Values Added
First Time appeared Nextcloud
Nextcloud nextcloud
Nextcloud nextcloud Enterprise Server
Nextcloud nextcloud Server
Nextcloud server
Vendors & Products Nextcloud
Nextcloud nextcloud
Nextcloud nextcloud Enterprise Server
Nextcloud nextcloud Server
Nextcloud server
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Nextcloud Server vulnerable to XSS in SVG images when opened outside of Nextcloud
Weaknesses CWE-80
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 5, 2025, 8:05 PM
Reserved
Dec 3, 2025, 3:28 PM
Status
Analyzed
Published
Dec 5, 2025, 5:16 PM
Modified
Oct 18, 2026, 2:10 PM