CVE-2026-9740: MongoDB

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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, where each re-entry resets internal depth tracking.

Affected products

• MongoDB MongoDB: from 7.0.0, before 7.0.35 (fixed in 7.0.35); from 8.0.0, before 8.0.24 (fixed in 8.0.24); from 8.2.0, before 8.2.10 (fixed in 8.2.10); from 8.3.0, before 8.3.3 (fixed in 8.3.3)

Published 2026-06-09. Last modified 2026-07-23.