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

Published Dec 5, 2025
·
Updated

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.

Affected Software

4 affected components
Nextcloud NextCloud Server<31.0.1
Nextcloud Nextcloud Enterprise Server<31.0.1
Nextcloud NextCloud Server>=31.0.0<31.0.1
Nextcloud NextCloud Server>=31.0.0<31.0.1

Event History

Dec 5, 2025
CVE Published
via MITRE·04:32 PM
Data Sourced
via MITRE·04:32 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:16 PM
RemedyDescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2025-66547?

CVE-2025-66547 is considered a moderate severity vulnerability due to improper access controls allowing non-privileged users to modify file tags.

2

How do I fix CVE-2025-66547?

To fix CVE-2025-66547, upgrade Nextcloud Server or Enterprise Server to version 31.0.1 or later.

3

Who is affected by CVE-2025-66547?

CVE-2025-66547 affects users of Nextcloud Server and Nextcloud Enterprise Server versions prior to 31.0.1.

4

What are the implications of CVE-2025-66547?

The implications of CVE-2025-66547 include unauthorized modification of file tags, which can lead to data misclassification or information leakage.

5

What is the nature of CVE-2025-66547?

CVE-2025-66547 is an access control vulnerability that allows unauthorized users to change tags on files they shouldn't access.

Contact

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