Integer Underflow in MongoDB's Key Management System
CVE-2026-106429

7.1HIGH

Key Information:

Vendor

Mongodb
Status
LIBMongocrypt
Vendor
CVE Published:
8 October 2026

What is CVE-2026-106429?

An integer underflow vulnerability exists in the KMS endpoint-parsing logic of MongoDB's libmongocrypt. This issue can lead to an allocation failure, resulting in abrupt termination of the application process. It could occur when an authenticated user modifies a key document within the key vault collection or when an application improperly accepts a KMS endpoint that includes a colon after the path or query during key creation, without accessing memory outside its allocated bounds.

Affected Version(s)

libmongocrypt 1.1.0 < 1.20.5

References

https://jira.mongodb.org/browse/MONGOCRYPT-986

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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