CVE 2011-3940
nsvdec.c in libavcodec in FFmpeg 0.7.x before 0.7.12 and 0.8.x before 0.8.11, and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.5, and 0.8.x before 0.8.1, allows remote attackers to cause a denial of service (out-of-bounds read and write) via a crafted NSV file that triggers "use of uninitialized streams."
See the 
CVE page on Mitre.org
for more details.
