The H.264 decoder in libstagefright in Android 6.x before 2016-04-01 mishandles Memory Management Control Operation (MMCO) data, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted media file, aka internal bug 25818142.
https://android.googlesource.com/platform/external/libavc/+/943323f1d9d3dd5c2634deb26cbe72343ca6b3db