CVE-2026-96749
HighCVSS 8.4Summary
An integer overflow exists in the BSON document encoding component of the MongoDB Python Driver's bundled native extension when a document is built from an unusually large amount of caller-supplied data. Size arithmetic uses a signed 32-bit type and the overflow guard has undefined behavior under the C standard. Depending on how the native extension was built, this can cause an out-of-bounds write within the application's own process.
Risk Assessment
An unauthenticated party able to place a very large value into data encoded by the application could trigger memory corruption in the application process, potentially leading to code execution or a crash.
Recommendation
Update the MongoDB Python Driver to a patched version and, where feasible, limit the size of caller-supplied data encoded to BSON.
Other vulnerabilities in MongoDB Python Driver
See all- CVE-2026-96747Medium
The client-side field level encryption support in the MongoDB Python Driver can treat a key management endpoint value ending in '.sock' as a local Unix domain socket path rather than a remote host. A user with write access to the encryption key metadata stored in the database can cause an application using the driver to open connections to local sockets on the application host. Data sent over these connections is limited to the start of a TLS handshake, so no chosen content is transmitted.
- CVE-2026-88029High
The GridFS component of the MongoDB Python Driver contains an improper neutralization of special elements in data query logic, where a caller-supplied structured file identifier can be interpreted as a query condition rather than a literal identifier. An authenticated user who can influence the identifier may obtain stored file content beyond the intended target, cause all GridFS file chunks in the affected bucket to be removed, or rename a stored file other than the intended target.
Original NVD description (English source)
An integer overflow in the BSON document encoding component of the MongoDB Python Driver's bundled native extension may occur when a single document is built from an unusually large amount of caller-supplied data. Size arithmetic is performed in a signed 32-bit type, and the guard meant to catch the overflow is written in a form whose behavior is not defined by the C language standard. A party with no privileges who can place a very large value into data that an application encodes may, depending on how the native extension was built, cause a write outside the bounds of an allocated buffer inside the application's own process.