/usr/include/xercesc/sax/ is in libxerces-c-dev 3.2.0+debian-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/xercesc/sax/AttributeList.hpp
/usr/include/xercesc/sax/DTDHandler.hpp
/usr/include/xercesc/sax/DocumentHandler.hpp
/usr/include/xercesc/sax/EntityResolver.hpp
/usr/include/xercesc/sax/ErrorHandler.hpp
/usr/include/xercesc/sax/HandlerBase.hpp
/usr/include/xercesc/sax/InputSource.hpp
/usr/include/xercesc/sax/Locator.hpp
/usr/include/xercesc/sax/Parser.hpp
/usr/include/xercesc/sax/SAXException.hpp
/usr/include/xercesc/sax/SAXParseException.hpp
/usr/include/xercesc/sax2/Attributes.hpp
/usr/include/xercesc/sax2/ContentHandler.hpp
/usr/include/xercesc/sax2/DeclHandler.hpp
/usr/include/xercesc/sax2/DefaultHandler.hpp
/usr/include/xercesc/sax2/LexicalHandler.hpp
/usr/include/xercesc/sax2/SAX2XMLFilter.hpp
/usr/include/xercesc/sax2/SAX2XMLReader.hpp
/usr/include/xercesc/sax2/XMLReaderFactory.hpp