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Vulnerability record · CVE-2025-66547 · published 5 December 2025

CVE-2025-66547: Nextcloud server insecure direct object reference vulnerability

Nextcloud · Nextcloud Server

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server and Enterprise Server prior to 31.0.1, non-privileged users can modify tags on files they should not have access to via bulk tagging. This vulnerability is fixed in 31.0.1.

4.3 CVSS 3.1 Medium EPSS 0.28% · top 81.7% CWE-639 · Insecure direct object reference
4.3CVSS 3.1 base score
0.28%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References
17 Jun 2026Last modified by NVD

Description

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server and Enterprise Server prior to 31.0.1, non-privileged users can modify tags on files they should not have access to via bulk tagging. This vulnerability is fixed in 31.0.1.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hq6c-r898-fgf2 PatchVendor Advisory
https://github.com/nextcloud/server/commit/b44f1568f2dc97c746281d99e2342ad679e3d8a9 Patch
https://github.com/nextcloud/server/issues/51247 Issue Tracking
https://github.com/nextcloud/server/pull/51288 Issue Tracking
https://hackerone.com/reports/3040887 Permissions RequiredVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-66547), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.