XSS in Nextcloud Contacts
CVE-2025-66554
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (12.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N.
Affected products
- Nextcloud Contacts
- Nextcloud Security-advisories — versions >= 7.0.0-alpha.1, < 7.2.5, >= 6.0.0-alpha1, < 6.0.6, < 5.5.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Permissions Required, x_refsource_MISC, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66554?
- CVE-2025-66554 is a low-severity vulnerability in Nextcloud Contacts, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2025-12-05.
- How severe is CVE-2025-66554?
- Low severity. CVSS v3 base score is 3.5 out of 10.