CVE-2025-66547
Nextcloud Server users can modify tags on files that do not belong to them
- State
- Published
- Severity
- 4.3 Medium
- Published
- Dec 5, 2025
- Updated
- Dec 5, 2025
- Reserved
- Dec 4, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N | GitHub_M |
Weaknesses
- CWE-639 Authorization Bypass Through User-Controlled Key
Affected Products
| Product | Versions |
|---|---|
security-advisoriesnextcloud |
|
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hq6c-r898-fgf2
- https://github.com/nextcloud/server/issues/51247
- https://github.com/nextcloud/server/pull/51288
- https://github.com/nextcloud/server/commit/b44f1568f2dc97c746281d99e2342ad679e3d8a9
- https://hackerone.com/reports/3040887
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