docx4j is an open source Java library for creating, editing, and saving OpenXML packages, including DOCX, PPTX, and XLSX files. Prior to 11.5.14, PropertyResolver and adjacent helpers recursively follow the WordprocessingML w:basedOn style inheritance chain without cycle detection. A well-formed DOCX containing mutually based styles causes unbounded recursion in PropertyResolver.fillPPrStack and related effective-style resolution paths, resulting in StackOverflowError. Server-side conversion and table-of-contents processing of an untrusted document can terminate a worker thread, degrade a thread pool, or deny service, although isolation in disposable workers or safe containment of StackOverflowError can reduce the practical effect. The fix adds cyclic-style tracking and CyclicStylesException handling. This issue is fixed in version 11.5.14.
https://github.com/plutext/docx4j/security/advisories/GHSA-gc95-3vw8-vg43
https://github.com/plutext/docx4j/releases/tag/docx4j-11.5.14
https://github.com/plutext/docx4j/commit/e06cafb334089f0be02e1c63a7c0a602bd44bf06
https://github.com/plutext/docx4j/commit/47b528c7dd4c81bcfc8e7fe9df7610c60446f95f