CVE-2025-66512

Dec. 9, 2025, 4:38 p.m.

5.4
Medium

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.

Product(s) Impacted

Vendor Product Versions
Nextcloud
  • Nextcloud Server
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-79
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
CWE-80
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a nextcloud nextcloud_server / / / / - / / /
a nextcloud nextcloud_server / / / / enterprise / / /
a nextcloud nextcloud_server / / / / - / / /
a nextcloud nextcloud_server / / / / enterprise / / /

CVSS Score

5.4 / 10

CVSS Data - 3.1

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Privileges Required: NONE
  • Scope: UNCHANGED
  • Confidentiality Impact: NONE
  • Integrity Impact: LOW
  • Availability Impact: LOW
  • CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

    View Vector String

Timeline

Published: Dec. 5, 2025, 5:16 p.m.
Last Modified: Dec. 9, 2025, 4:38 p.m.

Status : Analyzed

CVE has had analysis completed and all data associations made.

More info

Source

security-advisories@github.com

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.