CVE-2026-96749: mongodb python_driver Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-96749 is a high (CVSS 8.4) Integer Overflow or Wraparound vulnerability in mongodb python_driver. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.4% of scored vulnerabilities.

Timeline

1. 24-09-2026
   PublishedVulnerability first disclosed.
2. 26-09-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.