Papermerge Core through 3.5.3 contains a missing authorization vulnerability in the shared nodes API that allows authenticated users to share other users' documents by supplying arbitrary node UUIDs. Attackers can call POST /shared-nodes or PATCH /shared-nodes/access/{node_id} to grant themselves any role, then read, modify, or delete victims' documents and revoke existing shares.

Papermerge Core through 3.5.3 contains a missing authorization vulnerability in the shared nodes API that allows authenticated users to share other users' documents by supplying arbitrary node UUIDs. Attackers can call POST /shared-nodes or PATCH /shared-nodes/access/{node_id} to grant themselves any role, then read, modify, or delete victims' documents and revoke existing shares.