The default configuration for MongoDB before 2.3.2 does not validate objects, which allows remote authenticated users to cause a denial of service (crash) or read system memory via a crafted BSON object in the column name in an insert command, which triggers a buffer over-read.

MongoDB before 2.0.9 and 2.2.x before 2.2.4 does not properly validate requests to the nativeHelper function in SpiderMonkey, which allows remote authenticated users to cause a denial of service (invalid memory access and server crash) or execute arbitrary code via a crafted memory address in the first argument.

bson/_cbsonmodule.c in the mongo-python-driver (aka. pymongo) before 2.5.2, as used in MongoDB, allows context-dependent attackers to cause a denial of service (NULL pointer dereference and crash) via vectors related to decoding of an "invalid DBRef."