CVE-2026-82980

Arbitrary Cross‑User File Locking via WebDAV Paths

Published Sep 18, 2026 CVSS 3.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
Title Arbitrary Cross‑User File Locking via WebDAV Paths
Type Values Removed Values Added
Metrics ssvc

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
hackerone
Published
Updated
Sep 18, 2026, 7:42 PM
Reserved
Aug 31, 2026, 3:00 PM
Status
Deferred
Published
Sep 18, 2026, 2:17 AM
Modified
Sep 18, 2026, 8:17 PM