BIT-MONGODB-2026-9740 Unbounded recursion in BSONColumn interleaved-reference causes pre-auth stack overflow

A vulnerability in MongoDB Server's BSON validation logic allows an unauthenticated user to crash the mongod process by sending a specially crafted message. The BSON validator's handling of certain nested binary data structures permits uncontrolled mutual recursion between validation functions,...

CVE-2026-9740

Affected software: MongoDB Server. Vulnerability: BSON validation logic allows unauthenticated users to crash mongod via a specially crafted message. The BSON validator’s handling of certain nested binary data structures enables uncontrolled mutual recursion, where each re-entry resets internal d...