There is a heap-based buffer over-read in the Exiv2::Internal::PngChunk::keyTXTChunk function of pngchunk_int.cpp in Exiv2 0.26. A crafted PNG file will lead to a remote denial of service attack. Upstream issue: https://github.com/Exiv2/exiv2/issues/187
Created exiv2 tracking bugs for this issue: Affects: fedora-all [bug 1526053]