Description
Any authenticated user can lock or unlock files they do not own by targeting absolute WebDAV paths of other users. The DAV plugin resolves files from the absolute request URI without verifying that the path segment matches the authenticated session user. This enables:

Cross-user manual locks : attacker locks a victim's files, blocking writes (PUT/MOVE/DELETE, editor saves).
Lock-token disclosure: the app returns the lock token to unauthorized callers, enabling them to remove token-based locks (client locks) of other users.
Published: 2026-09-18
Score: 6.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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References
History

Sat, 19 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Title Arbitrary Cross‑User File Locking via WebDAV Paths

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 18 Sep 2026 11:15:00 +0000

Type Values Removed Values Added
First Time appeared Nextcloud
Nextcloud files Lock
Vendors & Products Nextcloud
Nextcloud files Lock

Fri, 18 Sep 2026 01:45:00 +0000

Type Values Removed Values Added
Description Any authenticated user can lock or unlock files they do not own by targeting absolute WebDAV paths of other users. The DAV plugin resolves files from the absolute request URI without verifying that the path segment matches the authenticated session user. This enables: Cross-user manual locks : attacker locks a victim's files, blocking writes (PUT/MOVE/DELETE, editor saves). Lock-token disclosure: the app returns the lock token to unauthorized callers, enabling them to remove token-based locks (client locks) of other users.
Weaknesses CWE-287
References
Metrics cvssV3_0

{'score': 6.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'}


Subscriptions

Nextcloud Files Lock
cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-09-18T19:42:58.732Z

Reserved: 2026-08-31T15:00:00.543Z

Link: CVE-2026-82980

cve-icon Vulnrichment

Updated: 2026-09-18T19:42:54.319Z

cve-icon NVD

Status : Deferred

Published: 2026-09-18T02:17:07.910

Modified: 2026-09-18T20:17:25.647

Link: CVE-2026-82980

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-19T21:15:06Z

Weaknesses