CVE-2019-13032
An issue was discovered in FlightCrew v0.9.2 and earlier. A NULL pointer dereference occurs in GetRelativePathToNcx() or GetRelativePathsToXhtmlDocuments() when a NULL pointer is passed to xc::XMLUri::isValidURI(). This affects third-party software (not Sigil) that uses FlightCrew as a library.
Source: CVE-2019-13032