CVE-2025-66510: nextcloud server — Fix

Description

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.

Is your site exposed to CVE-2025-66510?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

4.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N

Weakness Type (CWE)

CWE-359 CWE-359

Affected Products

Vendor	Product	Versions
nextcloud	nextcloud_server	28.0.0 — 28.0.14.11
nextcloud	nextcloud_server	29.0.0 — 29.0.16.8
nextcloud	nextcloud_server	30.0.0 — 30.0.17.3
nextcloud	nextcloud_server	31.0.0 — 31.0.10
nextcloud	nextcloud_server	31.0.0 — 31.0.10
nextcloud	nextcloud_server	32.0.0 — 32.0.1

References

Advisories & Patches

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-495w-cqv6-wr59 https://github.com/nextcloud/server/commit/e4866860cbf24a746eb8a125587262a4c8831c57

Other References

https://github.com/nextcloud/server/pull/55657

Frequently Asked Questions

What is CVE-2025-66510? +

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. It has a CVSS v3.1 base score of 4.5 (MEDIUM).

How severe is CVE-2025-66510? +

CVE-2025-66510 has a CVSS v3.1 score of 4.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-66510? +

CVE-2025-66510 affects products from nextcloud, specifically: nextcloud_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66510? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-62362

gpp-burgerportaal is a Dutch government citizen portal application. In versions before 2.0.3, 3.0.2, and 4.0.1, the name and email address …

CVE-2025-15623

Exposure of Private Personal Information to an Unauthorized Actor, : Exposure of Sensitive System Information to an Unauthorized Control Sphere …

CVE-2025-53625

The DynamicPageList3 extension is a reporting tool for MediaWiki, listing category members and intersections with various formats and details. Several …

CVE-2026-8990

A user with physical access to a smartphone can bypass authentication mechanism of Kidsview mobile application and grant himself full …

CVE-2025-5009

In Gemini iOS, when a user shared a snippet of a conversation, it would share the entire conversation via a …

CVE-2025-66035

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to versions …

CVE-2025-66510