The CJBig2_SymbolDict class in fxcodec/jbig2/JBig2_SymbolDict.cpp in PDFium, as used in Google Chrome before 47.0.2526.73, allows remote attackers to cause a denial of service (out-of-bounds memory access) or possibly have unspecified other impact via a PDF document containing crafted data with JBIG2 compression.