CVE-2025-64011
Medium
Description
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.
SeverityMedium
CVSS4.3
Exploit probability—
Product
Nextcloud Server
PublishedDec 12, 2025
First seenDec 12, 2025
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| nextcloud nextcloud_server | 30.0.0 | — |
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