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Fencer Vulns
medium 4.5

CVE-2025-66510 json

Nextcloud Server Contacts Search allowed users to retrieve contact information of other users beyond their contact list

published 2025-12-05 11 mo ago modified 2026-10-18 22 d ago also BIT-nextcloud-2025-66510 , EUVD-2025-201451 , GHSA-495w-cqv6-wr59

cvss
4.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami nextcloud 31.0.10, 32.0.1
  • nextcloud nextcloud 28.0.14.11, 29.0.16.8, 30.0.17.3, 31.0.10, 32.0.1
  • nextcloud nextcloud_server 28.0.14.11, 29.0.16.8, 30.0.17.3, 31.0.10, 32.0.1
  • nextcloud server 31.0.10, 32.0.1
  • nextcloud nextcloud_enterprise_server 28.0.14.11, 29.0.16.8, 30.0.17.3, 31.0.10

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-66510 updated cvss 4.5

nextcloud-server: Nextcloud Server Search allowed users to retrieve contact information of other users beyond their contact list

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
11 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
bitnami nextcloud
>=31.0.0, <31.0.10
>=32.0.0, <32.0.1
31.0.10
32.0.1

Affected products

  • nextcloud security-advisories

Classification

Weakness
  • CWE-359 Exposure of Private Personal Information to an Unauthorized Actor

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.