CVE-2025-66547

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.

Score

CVSS 3.1 4.3 Medium

Status

Analyzed - security-advisories@github.com

Published

2025-12-05

Last modified

2026-10-18

Weaknesses

CWE-639

Affected products

• Nextcloud Server (Nextcloud)
• Security-advisories (Nextcloud)

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