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
Impact: n/a
Action: n/a
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Remediation

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History

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

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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

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Weaknesses
  • CWE-681

    Incorrect Conversion between Numeric Types