Nextcloud Server/Enterprise Server Contacts Search private personal information

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.9$0-$5k0.00

Summaryinfo

A vulnerability has been found in Nextcloud Server and Enterprise Server and classified as problematic. The affected element is an unknown function of the component Contacts Search. The manipulation leads to private personal information. This vulnerability is referenced as CVE-2025-66510. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Nextcloud Server and Enterprise Server (the affected version unknown). This issue affects an unknown part of the component Contacts Search. The manipulation with an unknown input leads to a private personal information vulnerability. Using CWE to declare the problem leads to CWE-359. The product does not properly prevent a person's private, personal information from being accessed by actors who either (1) are not explicitly authorized to access the information or (2) do not have the implicit consent of the person about whom the information is collected. Impacted is confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-66510 since 12/03/2025. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation requires an enhanced level of successful authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1589 for this issue.

Upgrading eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.9
VulDB Meta Temp Score: 3.9

VulDB Base Score: 2.4
VulDB Temp Score: 2.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.9
NVD Vector: 🔒

CNA Base Score: 4.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Private personal information
CWE: CWE-359
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

12/03/2025 CVE reserved
12/05/2025 +2 days Advisory disclosed
12/05/2025 +0 days VulDB entry created
12/11/2025 +6 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-66510 (🔒)
GCVE (CVE): GCVE-0-2025-66510
GCVE (VulDB): GCVE-100-334505

Entryinfo

Created: 12/05/2025 17:57
Updated: 12/11/2025 03:51
Changes: 12/05/2025 17:57 (62), 12/11/2025 03:51 (11)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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