Description
A numeric-type conversion flaw in the BSON handling library of the MongoDB C# Driver allows an out-of-range binary subtype value supplied through untrusted textual input to bypass the library's binary-element integrity checks. When such a value is later encoded, it is narrowed to a smaller wire representation, producing binary elements that misdeclare their type or length. An unauthenticated party able to supply text parsed by an affected application can cause it to emit and persist malformed binary data, which subsequent readers either reject with an error or silently interpret as shorter than the data that was validated.
Published: 2026-10-22
Score: 6.9 Medium
EPSS: n/a
KEV: No
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No solution or workaround provided in the CVE record.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Fri, 23 Oct 2026 05:00:00 +0000

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb c# Driver
Vendors & Products Mongodb
Mongodb c# Driver

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Description A numeric-type conversion flaw in the BSON handling library of the MongoDB C# Driver allows an out-of-range binary subtype value supplied through untrusted textual input to bypass the library's binary-element integrity checks. When such a value is later encoded, it is narrowed to a smaller wire representation, producing binary elements that misdeclare their type or length. An unauthenticated party able to supply text parsed by an affected application can cause it to emit and persist malformed binary data, which subsequent readers either reject with an error or silently interpret as shorter than the data that was validated.
Title BSON output corruption via out-of-range binary subtype bypassing UUID and OldBinary guards
Weaknesses CWE-681
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}


Subscriptions

Mongodb C# Driver
cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-10-22T21:25:37.785Z

Reserved: 2026-10-21T21:57:56.257Z

Link: CVE-2026-114654

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-22T19:17:39.547

Modified: 2026-10-22T22:18:06.203

Link: CVE-2026-114654

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T04:45:13Z

Weaknesses