CVE-2025-66554

3.5 LOW
Published: December 05, 2025 Modified: December 09, 2025

Description

Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/nextcloud/contacts/pull/4619
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2
Source: security-advisories@github.com
Patch Vendor Advisory
https://hackerone.com/reports/3293290
Source: security-advisories@github.com
Permissions Required Vendor Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
3.5 / 10.0
EPSS (Exploit Probability)
0.0%
3th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

nextcloud