Octobre 2026

MongoDB C# Driver

The MongoDB C# Driver does not reject replacement documents whose top-level field names begin with a dollar sign in FindOneAndReplace, unlike other replace operations. An application that builds such a document from user-supplied field names can have the server apply update operators instead of a full replacement. The effect is limited to the document matched by the application's own filter, whose contents can be modified in ways the application did not intend.

MongoDB C# Driver

The MongoDB C# Driver's BSON library contains an uncontrolled resource consumption weakness in its deserialization handling of one BSON value type. An application that deserializes untrusted content with the library retains data derived from that content for the lifetime of the process, with no limit on how much accumulates. An unauthenticated remote party who can cause such content to be deserialized can drive unbounded memory growth, exhausting the host application's available memory and denying service. There is no impact to confidentiality or integrity, and no MongoDB server component is affected.

MongoDB C# Driver

The MongoDB C# Driver writes GeoJSON extra members without checking whether their names collide with reserved GeoJSON members such as type and coordinates. An application that places user-supplied field names into these extra members can store documents with duplicate geometry fields, so the server and the driver resolve different values for the same record. Affected records can also become unreadable through the driver, interrupting application code that reads them.

MongoDB Server

A security issue was discovered in MongoDB mongos (the sharded cluster router) where an authenticated user with readWrite privileges could crash the mongos process by crafting a specially formed aggregation pipeline. The issue leverages an internal aggregation stage that lacks proper authorization checks despite being intended for internal use, allowing a subsequent stage to be forced to execute on the router under conditions it was not designed to handle. This results in an unhandled fatal error that causes the mongos process to immediately abort, resulting in denial of service for all clients routed through the affected mongos instance.

MongoDB Server

Use of freed memory in the aggregation feature of MongoDB Server can cause the server to read data from a memory area after it has been released. When an internal aggregation stage is combined with a batch size of 0, the server may read from memory that is no longer in use. Because that memory can be reused for other data before it is read, query results returned to the client may contain unrelated data from the server process. Depending on the state of memory at the time, the server process may also terminate unexpectedly. The behavior can occur when an authenticated user with read privileges runs an aggregate command that combines these two settings.

MongoDB Server

A security issue was discovered in MongoDB mongos (the sharded cluster router) where an authenticated user with readWrite privileges could crash the mongos process by crafting a specially formed aggregation pipeline. The issue leverages an internal aggregation stage that lacks proper authorization checks despite being intended for internal use, allowing a subsequent stage to be forced to execute on the router under conditions it was not designed to handle. This results in an unhandled fatal error that causes the mongos process to immediately abort, resulting in denial of service for all clients routed through the affected mongos instance.

MongoDB Server

MongoDB Server's collection validation feature may not properly handle certain expressions stored in a validator. In some cases, this can cause the server process to stop running when a document is later inserted. The behavior can occur for authenticated users with write access.

MongoDB Server

An issue in MongoDB Server's aggregation framework can cause certain constant values to be handled incorrectly during internal query rewriting. Under certain conditions, an authenticated user with read access may receive field values in aggregation output that the query did not intend to return.

parse-community parse-server

Parse Server 5.4.0 before 8.6.96 and 9.0.0 before 9.10.2-alpha.5 shares transactional batch state across concurrent requests, letting any client's transactional batch request interfere with other clients' database writes. On PostgreSQL or MongoDB replica sets and sharded clusters, other clients' acknowledged writes are rolled back if the batch fails, and PostgreSQL transactions can remain open indefinitely, causing subsequent writes to fail.

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

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 libmongocrypt

The explicit decryption component of MongoDB libmongocrypt can return an unrecognized encrypted payload unchanged instead of returning a decryption error. An actor who can modify stored encrypted fields, such as a database writer, server, or network intermediary, can cause an affected application to process the supplied bytes as decrypted plaintext.

langchain-ai langchainjs · @langchain mongodb

LangChain is a framework for building LLM-powered applications. Prior to 1.3.1, MongoDBChatMessageHistory does not enforce the documented string type for an untrusted structured session identifier at runtime, allowing the identifier to be interpreted as a MongoDB query condition rather than as a literal value when multiple users' histories are stored in a shared MongoDB collection. An attacker able to invoke chat-history operations can read, modify, or delete another user's stored conversation. Applications using authenticated, server-controlled string identifiers are not affected. This issue is fixed in version 1.3.1.