CVE-2026-3089: Actualbudget Actual

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Actualbudget Actual: before 26.3.0 (fixed in 26.3.0)

Published 2026-03-09. Last modified 2026-06-17.