CVE-2025-66510
Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.5
Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list
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.
- Record
CVE-2025-66510- CVSS 3.1
- 4.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-359
- Updated
- 2026-11-02
EUVDEUVD-2025-201451
4.5
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.
- Record
EUVD-2025-201451- CVSS 3.1
- 4.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
NVD
4.5
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.
- Record
CVE-2025-66510- CVSS 3.1
- 4.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N - CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-359
- Updated
- 2026-11-02
OSV
4.5
Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list
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.
- Record
CVE-2025-66510- CVSS 3.1
- 4.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-359
- Updated
- 2026-11-02
OSVBIT-nextcloud-2025-66510 No score
Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list
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.
- Record
BIT-nextcloud-2025-66510- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nextcloudBitnami |
31.0.0 up to 31.0.10, 32.0.0 up to 32.0.1 | 31.0.1032.0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-66510 is a medium vulnerability (CVSS 4.5) in Nextcloud Server, published December 5, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. Fixed in nextcloud 31.0.10.
References
github.com/nextcloud/security-advisories/security/advisories/GHSA-495w-cqv6-wr59
github.com/nextcloud/server/pull/55657
github.com/nextcloud/server/commit/e4866860cbf24a746eb8a125587262a4c8831c57
nvd.nist.gov/vuln/detail/CVE-2025-66510
github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66510.json