Octobre 2026

MongoDB Python Driver

The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON containing a truncated regular-expression element without a trailing NUL byte. An actor who can supply BSON to the documented decode or decode_all API can cause the application process to terminate when the C extension is loaded. The driver's normal database wire-protocol path does not reach this code.

MongoDB PHP Driver

The BSON encoder in the MongoDB PHP Driver does not check some return values after a document exceeds libbson's size limit. This can leave the encoder in an invalid state. An unauthenticated actor who can cause an affected application to encode an unusually large data structure can terminate the PHP worker or cause the resulting document to omit fields. No MongoDB server connection or database authentication is required.

MongoDB Go Driver

Improper validation of a BSON array length in the MongoDB Go Driver can cause an out-of-bounds index and runtime panic when an application calls bson.RawArray.Validate or bsoncore.Array.Validate on a malformed four-byte array. An unauthenticated actor who can supply raw BSON array data to an affected application may terminate an unprotected application process, causing a denial of service. No confidentiality or integrity impact has been identified.

MongoDB Go Driver

An integer overflow in BSON value-length handling in the MongoDB Go Driver can cause a runtime panic when an application validates or accesses a malformed BSON document. An unauthenticated actor who can supply BSON bytes to an affected application may terminate an unprotected application process, causing a denial of service. The driver's server-monitoring path contains panic recovery and is limited to server-selection failure.

MongoDB C Driver

An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver can accept certain over-precision inputs containing leading zeros instead of rejecting them. This produces a value different from the supplied text. An actor who can provide a decimal string to an embedding application, including through Extended JSON parsing, can cause the application to store or use an incorrect numeric value.

MongoDB C Driver

The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller than the five-byte BSON minimum. Later append or comparison operations can underflow unsigned length calculations and read or write outside the document buffer. An actor who can influence the length supplied by an embedding application can cause the application to terminate or read or corrupt adjacent process memory. Reaching this issue requires the application to pass an undersized value to bson_reserve_buffer and then perform an affected operation.

MongoDB C Driver

An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process. Reaching this issue requires the application to use the BSON bulk-writer API and produce a precise cumulative document size.

MongoDB C++ Driver

The MongoDB C++ Driver discards content after an embedded NUL byte in certain field and collection names accepted by the collection API. This can cause the driver and the calling application to interpret the same name differently. An authenticated actor who can influence a name passed by an affected application can cause the application to read distinct values from an unintended field or rename an unintended collection. These operations use the application's existing database credentials.