CVE-2026-82980 Missing authorization in Files Lock
Authenticated users can lock or unlock other users' files via WebDAV paths, causing denial of service and bypassing lock protections.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82980?
CVE-2026-82980 is a medium-severity missing authorization vulnerability in Nextcloud Files Lock, published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-287
Which versions are affected by CVE-2026-82980?
How do I fix CVE-2026-82980?
No fix has been published for CVE-2026-82980 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-82980 being exploited?
There is no known exploitation of CVE-2026-82980 in the wild and no public exploit code.
Sources
Also known as GHSA-3vwx-p83m-w7p5.