The various bsonappend functions in the MongoDB C driver library may be susceptible to buffer overflow when performing operations that could result in a final BSON document which exceeds the maximum allowable size (INT32MAX), resulting in a segmentation fault and possible application crash. This issue affected libbson versions prior to 1.27.5, MongoDB Server v8.0 versions prior to 8.0.1 and MongoDB Server v7.0 versions prior to 7.0.16

bsoniternextinternal in bson-iter.c in libbson 1.12.0, as used in MongoDB mongo-c-driver and other products, has a heap-based buffer over-read via a crafted bson buffer.

A missing bounds check in the BSON CodeWScope element accessors allows an attacker to trigger an out-of-bounds heap read via a crafted aggregation pipeline. The vulnerability can be exploited by an authenticated user by generating a malformed BSONColumn data containing a CodeWScope element, bypassing wire-level BSON validation. When the forged element is decompressed, the unchecked size value is used in pointer arithmetic, causing either a server crash or disclosure of adjacent heap memory contents.

An integer wraparound in an allocation size calculation in the BSON library's JSON parsing code can cause a buffer to be released while a following copy operation still writes through the stale pointer. On builds where sizes are 32 bits, an unauthenticated party able to supply a sufficiently large JSON input to an application that links the library may cause that application to terminate unexpectedly, resulting in denial of service.