pi.c in OpenJPEG, as used in PDFium in Google Chrome before 48.0.2564.109, does not validate a certain precision value, which allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds read) via a crafted JPEG 2000 image in a PDF document, related to the opj_pi_next_rpcl, opj_pi_next_pcrl, and opj_pi_next_cprl functions.