In Exiv2 0.26, there is a heap-based buffer over-read in the Exiv2::IptcData::printStructure function in iptc.cpp, related to the "!= 0x1c" case. Remote attackers can exploit this vulnerability to cause a denial of service via a crafted TIFF file.
https://access.redhat.com/errata/RHSA-2019:2101
https://bugzilla.redhat.com/show_bug.cgi?id=1524107
https://github.com/Exiv2/exiv2/issues/263