This file depicts the flag of a German Körperschaft des öffentlichen Rechts (corporation governed by public law). According to § 5 Abs. 1 of the German Copyright law, official works like flags are gemeinfrei (in the public domain).
Note: The usage of flags is governed by legal restrictions, independent of the copyright status of the depiction shown here.

This image is in the public domain according to Article 4, case 2 of the Polish Copyright Law Act of February 4, 1994 (Dz. U. z 2022 r. poz. 2509 with later changes) "normative acts and drafts thereof as well as official documents, materials, signs and symbols are not subject to copyrights". Hence it is assumed that this image has been released into public domain. However in some instances the use of this image in Poland might be regulated by other laws.