Nextcloud Server Vulnerability in files_lock App - Open Source Collaboration Platform
CVE-2026-45283

6.3MEDIUM

Key Information:

Vendor

Nextcloud
Status
Security-advisories
Vendor
CVE Published:
1 June 2026

What is CVE-2026-45283?

A significant security issue has been identified in the files_lock app of Nextcloud Server, affecting versions 32.0.0 through 32.0.1 and 33.0.0 through 33.0.1. This vulnerability allows an authenticated user to misuse the WebDAV locking mechanism, enabling them to lock or unlock files owned by other users through direct manipulation of their absolute WebDAV paths. Furthermore, the app improperly discloses lock tokens in error responses, which could allow an attacker to remove lock tokens created by other users' applications. To mitigate this risk, it is strongly advised that users upgrade their Nextcloud Servers to the latest recommended versions.

Affected Version(s)

security-advisories >= 32.0.0, < 32.0.2 < 32.0.0, 32.0.2

security-advisories >= 33.0.0, < 33.0.1 < 33.0.0, 33.0.1

References

https://github.com/nextcloud/security-advisories/security...
x_refsource_CONFIRM
https://github.com/nextcloud/files_lock/pull/1007
x_refsource_MISC
https://hackerone.com/reports/3301553#
x_refsource_MISC

CVSS V3.1

Score:
6.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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