A buffer overflow vulnerability exists in the MongoDB C driver bson library's bson_append functions when constructing BSON documents that exceed the maximum size limit (INT32_MAX). This can cause segmentation faults and application crashes. The issue affects libbson versions prior to 1.27.5, MongoDB Server v7.0 versions before 7.0.16, and MongoDB Server v8.0 versions before 8.0.1. A patch is available to address this vulnerability.