Vulnerability Report

CVE-2026-45283

Title: Files_lock app improper ownership validation

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2026-45283.

CWE Category CWE-287
Published Date Jun 01, 2026
Modified Date Jun 03, 2026
Exploit Status Not Found
Score 6.3 CVSS v3.1
Exploit Probability (EPSS)
0.01%

Vulnerability Summary

CVE-2026-45283: Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users' client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1

Impacted Vendors

N
nextcloud 1

Reference Links

https://github.com/nextcloud/files_lock/pull/1007 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj https://hackerone.com/reports/3301553#
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
4.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-45283 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected Stack

No specific products linked.