PDF Labs pdftk-java v3.2.3 was discovered to contain an infinite loop via the component /text/pdf/PdfReader.java. https://gitlab.com/pdftk-java/pdftk/-/merge_requests/21/diffs?commit_id=9b0cbb76c8434a8505f02ada02a94263dcae9247#diff-content-b3cfd29983c793bcae2375502abd5baa8f5d1081
Please note that pdftk-java is not by PDF Labs, it is a GCJ-free port of PDF Labs PDFtk. Aside of that the affected version v3.2.3 was never part of Fedora, the earliest packaged version in Fedora is v3.3.1.