CVE-2025-66554
Nextcloud Contacts vulnerable to Stored XSS in contacts app via organisation and title field
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.
INFO
Published Date :
Dec. 5, 2025, 6:15 p.m.
Last Modified :
Dec. 9, 2025, 5:01 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Nextcloud Contacts app to version 5.5.4 or later.
- Update the Nextcloud Contacts app to version 6.0.6 or later.
- Update the Nextcloud Contacts app to version 7.2.5 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66554.
| URL | Resource |
|---|---|
| https://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1 | Patch |
| https://github.com/nextcloud/contacts/pull/4619 | Issue Tracking Patch |
| https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2 | Patch Vendor Advisory |
| https://hackerone.com/reports/3293290 | Permissions Required Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66554 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66554
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66554 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66554 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Dec. 09, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Added CPE Configuration OR *cpe:2.3:a:nextcloud:contacts:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.5.4 *cpe:2.3:a:nextcloud:contacts:*:*:*:*:*:*:*:* versions from (including) 6.0.0 up to (excluding) 6.0.6 *cpe:2.3:a:nextcloud:contacts:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (excluding) 7.2.5 Added Reference Type GitHub, Inc.: https://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/nextcloud/contacts/pull/4619 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2 Types: Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://hackerone.com/reports/3293290 Types: Permissions Required, Vendor Advisory -
New CVE Received by [email protected]
Dec. 05, 2025
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N Added CWE CWE-79 Added Reference https://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1 Added Reference https://github.com/nextcloud/contacts/pull/4619 Added Reference https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2 Added Reference https://hackerone.com/reports/3293290