1. Home
  2. CVE Database
  3. CVE-2026-9740
HIGH · 7.5

CVE-2026-9740

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 ne...

Vulnerability Description

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.

CVSS Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
MongodbMongodb>= 7.0.0, < 7.0.35

Related Weaknesses (CWE)

CWE-674

References

FAQ

What is CVE-2026-9740?

CVE-2026-9740 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ne...

How severe is CVE-2026-9740?

CVE-2026-9740 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-9740?

Check the references section above for vendor advisories and patch information. Affected products include: Mongodb Mongodb.