Is CVE-2026-45283 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-45283 being exploited in the wild.

How severe is CVE-2026-45283?

Medium severity, with a CVSS score of 6.3, published 1 June 2026.

Which products and versions are affected?

Nextcloud Nextcloud Server 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1; Nextcloud Nextcloud Enterprise Server 31.0.0 to < 31.0.14.4, 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1.

Is there a fix for CVE-2026-45283?

A patch was published on 2026-02-24: Fix merged in files_lock repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-45283 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-45283?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-45283: Nextcloud Server improper authentication in files_lock app

Q: Is there a fix for CVE-2026-45283?

A patch was published on 2026-02-24: Fix merged in files_lock repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-45283 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-45283?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-45283 · Severity: medium · CVSS 6.3 · Published 2026-06-01

Nextcloud is an open-source platform used by organizations for file sharing and collaboration. A security flaw in the file locking system allows logged-in users to lock or unlock files belonging to other people without permission. This could disrupt business operations by preventing legitimate users from editing their documents or by removing protections intended to prevent simultaneous file edits.

Quick answers

Is CVE-2026-45283 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-45283 being exploited in the wild.
How severe is CVE-2026-45283?: Medium severity, with a CVSS score of 6.3, published 1 June 2026.
Which products and versions are affected?: Nextcloud Nextcloud Server 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1; Nextcloud Nextcloud Enterprise Server 31.0.0 to < 31.0.14.4, 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1.
Is there a fix for CVE-2026-45283?: A patch was published on 2026-02-24: Fix merged in files_lock repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45283 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-45283?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An improper authentication vulnerability (CWE-287) exists in the Nextcloud 'files_lock' application due to insufficient ownership validation during WebDAV lock and unlock requests. By targeting absolute WebDAV paths, an authenticated attacker can manipulate file locks belonging to other users. Furthermore, the application leaks lock tokens in error responses, which allows unauthorized callers to bypass and remove token-based locks established by other client applications. The issue is resolved in Nextcloud Server versions 32.0.2 and 33.0.1, and Enterprise Server versions 31.0.14.4, 32.0.2, and 33.0.1.

Affected products

Nextcloud Nextcloud Server 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1
Nextcloud Nextcloud Enterprise Server 31.0.0 to < 31.0.14.4, 32.0.0 to < 32.0.2, 33.0.0 to < 33.0.1

Timeline

2026-02-24: patched: Fix merged in files_lock repository
2026-05-12: advisory: GitHub security advisory published
2026-06-01: disclosed: NVD publication date

References

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