Vulnerability in Contacts App for Nextcloud Allows Malicious CSS Manipulation
CVE-2025-66554

3.5LOW

Key Information:

Vendor

Nextcloud

Vendor
CVE Published:
5 December 2025

What is CVE-2025-66554?

The Contacts app for Nextcloud, which synchronizes and allows editing of contacts from various devices, is susceptible to a vulnerability that permits a malicious user to inject custom CSS files by altering their organization and title fields. This occurs before the app versions 5.5.4, 6.0.6, and 7.2.5, where the content security policy effectively blocks JavaScript and other potentially harmful options. The issue has been addressed in later versions, enhancing the security posture of the application.

Affected Version(s)

security-advisories >= 7.0.0-alpha.1, < 7.2.5 < 7.0.0-alpha.1, 7.2.5

security-advisories >= 6.0.0-alpha1, < 6.0.6 < 6.0.0-alpha1, 6.0.6

security-advisories < 5.5.4 < 5.5.4

References

CVSS V3.1

Score:
3.5
Severity:
LOW
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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