From NVD
Use-after-free vulnerability in the imgContainer::InternalAddFrameHelper function in src/imgContainer.cpp in libpr0n in Mozilla Firefox 3.6 before 3.6.2 allows remote attackers to cause a denial of service (heap memory corruption and application crash) or possibly execute arbitrary code via a multipart/x-mixed-replace animation in which the frames have different bits-per-pixel (bpp) values.