CVE-2026-105633 Plane: Issue Attachment Ownership Hijacking via Missing `issue_id` Scope
Attackers can hijack attachment ownership by exploiting missing issue_id scope checks in the PATCH endpoint, allowing unauthorized modification of other users' files.
- 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-2026-105633?
CVE-2026-105633 is a high-severity missing authorization vulnerability in makeplane plane, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Plane is an open-source project management tool. Prior to 1.4.0, the V2 issue-attachment PATCH endpoint accepts issue_id in the URL but omits it from the database query. A project member can use an issue_id they control in the URL while targeting another user's attachment by its pk UUID. Because the server matches only pk, workspace, and project_id, it modifies the attachment regardless of the issue_id in the URL. When the attachment is pending and has not been confirmed as uploaded, the PATCH handler sets created_by = request.user and transfers attachment ownership to the attacker. This issue is fixed in 1.4.0.
Weakness: CWE-639
Which versions are affected by CVE-2026-105633?
How do I fix CVE-2026-105633?
No fix has been published for CVE-2026-105633 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-2026-105633 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105633 exists.
Sources
Also known as GHSA-5mxw-g5mw-3v3w.