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.
References
https://gist.github.com/tarekramm/586dfe2d113fedfee6d71182570fc090
ExploitThird Party Advisory
Product
CVSS impact metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.3 · Medium
CVSS V3.1
CVSS V3.0
CVSS V2.0
Information
Source identifier
Vulnerability status
Analyzed
Published
2025-12-12T17:15:45.210
1 week agoLast modified
2025-12-19T15:47:19.010
3 hours ago