Nextcloud Server <31.0.10 / 32.0.1 Contact Search Data Leak
CVE-2025-66510 Published on December 5, 2025
Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list
Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server prior to 31.0.10 and 32.0.1 and Nextcloud Enterprise Server prior to 28.0.14.11, 29.0.16.8, 30.0.17.3, and 31.0.10, contacts search allowed to retrieve personal data of other users (emails, names, identifiers) without proper access control. This allows an authenticated user to retrieve information about accounts that are not related or added as contacts.
Vulnerability Analysis
CVE-2025-66510 is exploitable with network access, requires user interaction and user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Type
What is a Privacy violation Vulnerability?
The product does not properly prevent a person's private, personal information from being accessed by actors who either (1) are not explicitly authorized to access the information or (2) do not have the implicit consent of the person about whom the information is collected.
CVE-2025-66510 has been classified to as a Privacy violation vulnerability or weakness.
Products Associated with CVE-2025-66510
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Affected Versions
nextcloud security-advisories:- Version >= 32.0.0beta1, < 32.0.1 is affected.
- Version < 31.0.10 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.