The EbmlUnicodeString::UpdateFromUTF8 function in libEBML before 1.3.3 allows context-dependent attackers to obtain sensitive information from process heap memory via a crafted UTF-8 string, which triggers an invalid memory access.
https://github.com/Matroska-Org/libebml/commit/ababb64e0c792ad2a314245233db0833ba12036b
https://github.com/Matroska-Org/libebml/blob/release-1.3.3/ChangeLog
http://www.talosintelligence.com/reports/TALOS-2016-0036/
http://www.securityfocus.com/bid/95124
http://www.securityfocus.com/bid/85307
http://www.debian.org/security/2016/dsa-3538
http://lists.opensuse.org/opensuse-updates/2016-01/msg00035.html
http://lists.matroska.org/pipermail/matroska-users/2015-October/006985.html