Vulnerability Report

CVE-2025-66554

Title: Nextcloud Contacts app CSS Injection

XSS

Proof Of Concept

No public PoC currently indexed for CVE-2025-66554.

CWE Category CWE-79
Published Date Dec 05, 2025
Modified Date Dec 09, 2025
Exploit Status Not Found
Score 3.5 CVSS v3.1
Exploit Probability (EPSS)
0.02%

Vulnerability Summary

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.

Impacted Vendors

N
nextcloud 1

Reference Links

https://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1 https://github.com/nextcloud/contacts/pull/4619 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2 https://hackerone.com/reports/3293290
CVSS v3.1
Source Entity [email protected]
Severity LOW
3.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.4
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2025-66554 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

MODIFIED

Vulnerability data updated via NVD.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Affected Stack

No specific products linked.