Medium (5.3) in actualbudget actual. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in @actual-app/sync-server 26.3.0.
Actual Sync Server allows authenticated users to upload files through POST /sync/upload-user-file. In versions prior to 26.3.0, improper validation of the user-controlled x-actual-file-id header means that traversal segments (../) can escape the intended directory and write files outside userFiles.This issue affects prior versions of Actual Sync Server 26.3.0.