Medium 4.3Published Dec 5, 2025

CVE-2025-66547Nextcloud Server users can modify tags on files that do not belong to them

Updated under an hour ago (Oct 26, 2026, 11:50 PM ET)

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It affects nextcloud security-advisories and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for nextcloud security-advisories

Exploited in the last 30 days

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: 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-639
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Dec 5, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

nextcloud security-advisories nextcloud:security_advisories (from the name)	before 31.0.1	CNA record
nextcloud nextcloud_server nextcloud:nextcloud_server	from 31.0.0 before 31.0.1; from 31.0.0 before 31.0.1	NVD

References

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hq6c-r898-fgf2	x-refsource-confirm, patch, vendor-advisory
https://github.com/nextcloud/server/issues/51247	x-refsource-misc, issue-tracking
https://github.com/nextcloud/server/pull/51288	x-refsource-misc, issue-tracking
https://github.com/nextcloud/server/commit/b44f1568f2dc97c746281d99e2342ad679e3d8a9	x-refsource-misc, patch
https://hackerone.com/reports/3040887	x-refsource-misc, permissions-required, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.