In DjVuLibre 3.5.27, the sorting functionality (aka GArrayTemplate<TYPE>::sort) allows attackers to cause a denial-of-service (application crash due to an Uncontrolled Recursion) by crafting a PBM image file that is mishandled in libdjvu/GContainer.h.
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.