PT-2025-50959 · Nextcloud · Nextcloud Server

Tarek Ramadan · Published 2025-12-12 · Updated 2025-12-19 · CVE-2025-64011

Positive Technologies (AI Summary)

CVSS v3.1

4.3

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Nextcloud Server version 30.0.0

Description Nextcloud Server 30.0.0 contains an Insecure Direct Object Reference (IDOR) issue in the /core/preview endpoint. An 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. An IDOR occurs when an application provides direct access to objects based on user-supplied input.

Recommendations Nextcloud Server version 30.0.0: Restrict access to the /core/preview endpoint or implement stricter access controls to prevent unauthorized file preview access.

Exploit

Fix

IDOR

Weakness Enumeration

CWE-639

Related Identifiers

CVE-2025-64011

Affected Products

Nextcloud Server

References · 9

• 🔥 https://gist.github.com/tarekramm/586dfe2d113fedfee6d71182570fc090 · Exploit
• 🔥 https://drive.google.com/file/d/1eD3PN-u1caZYgGH96XHmJ7h_OBXEAHW4/view?usp=sharing · Exploit
• https://osv.dev/vulnerability/CVE-2025-64011 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-64011 · Security Note
• https://twitter.com/CVEnew/status/1999876854975541474 · Twitter Post
• https://nextcloud.com · Note
• https://t.me/CVEtracker/39641 · Telegram Post
• https://t.me/cveNotify/146336 · Telegram Post
• https://twitter.com/VulmonFeeds/status/1999624077200273901 · Twitter Post