Privilege Escalation in Nextcloud Server Affects User File Tagging
CVE-2025-66547

4.3MEDIUM

Key Information:

Vendor

Nextcloud
Status
Security-advisories
Vendor
CVE Published:
5 December 2025

What is CVE-2025-66547?

In Nextcloud Server and Nextcloud Enterprise Server versions prior to 31.0.1, a vulnerability allows non-privileged users to alter file tags they do not have permission to modify by utilizing the bulk tagging feature. This unauthorized access can lead to improper file categorization and potential data leakage. The issue has been addressed in version 31.0.1, enhancing the security of user permissions.

Affected Version(s)

security-advisories < 31.0.1

References

https://github.com/nextcloud/security-advisories/security...
x_refsource_CONFIRM
https://github.com/nextcloud/server/issues/51247
x_refsource_MISC
https://github.com/nextcloud/server/pull/51288
x_refsource_MISC

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.