Stack consumption vulnerability in libxml2 2.5.10, 2.6.16, 2.6.26, 2.6.27, and 2.6.32, and libxml 1.8.17, allows context-dependent attackers to cause a denial of service (application crash) via a large depth of element declarations in a DTD, related to a function recursion, as demonstrated by the Codenomicon XML fuzzing framework.