Description
A weakness in the BSON library's handling of a specialized binary vector data type allows an arithmetic wraparound when computing the number of elements described by an oversized attacker-supplied value. On builds where the platform word size is 32 bits, an application that parses untrusted BSON data can be made to process only a small fraction of the supplied elements while the operation reports success, producing results that disagree with byte-oriented accessors and with 64-bit builds of the same library. No authentication or user interaction is required beyond getting the application to parse the data. The impact is limited to data integrity; memory safety is not affected and no information is disclosed.
Published: 2026-11-03
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Tue, 03 Nov 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 03 Nov 2026 19:00:00 +0000

Type Values Removed Values Added
Description A weakness in the BSON library's handling of a specialized binary vector data type allows an arithmetic wraparound when computing the number of elements described by an oversized attacker-supplied value. On builds where the platform word size is 32 bits, an application that parses untrusted BSON data can be made to process only a small fraction of the supplied elements while the operation reports success, producing results that disagree with byte-oriented accessors and with 64-bit builds of the same library. No authentication or user interaction is required beyond getting the application to parse the data. The impact is limited to data integrity; memory safety is not affected and no information is disclosed.
Title Silent element-count truncation via 32-bit bit-length overflow in packed-bit vector views
Weaknesses CWE-190
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-11-03T19:42:13.241Z

Reserved: 2026-11-03T03:14:08.527Z

Link: CVE-2026-120954

cve-icon Vulnrichment

Updated: 2026-11-03T19:42:09.016Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-03T19:18:00.470

Modified: 2026-11-03T20:18:12.557

Link: CVE-2026-120954

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses