Nextcloud Server 30.0.0 IDOR via /core/preview fileId
CVE-2025-64011 Published on December 12, 2025
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.
Vulnerability Analysis
CVE-2025-64011 can be exploited with network access, and requires small amount of 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 small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is an Insecure Direct Object Reference / IDOR Vulnerability?
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CVE-2025-64011 has been classified to as an Insecure Direct Object Reference / IDOR vulnerability or weakness.
Products Associated with CVE-2025-64011
Want to know whenever a new CVE is published for Nextcloud Server? stack.watch will email you.
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.