CVE 2012-3425
The png_push_read_zTXt function in pngpread.c in libpng 1.0.x before 1.0.58, 1.2.x before 1.2.48, 1.4.x before 1.4.10, and 1.5.x before 1.5.10 allows remote attackers to cause a denial of service (out-of-bounds read) via a large avail_in field value in a PNG image.
See the 
CVE page on Mitre.org
for more details.
