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://security.gentoo.org/glsa/201811-14
https://github.com/xiaoqx/pocs/blob/master/exiv2/readme.md