Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.

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History

Thu, 03 Sep 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb libmongocrypt
Vendors & Products Mongodb
Mongodb libmongocrypt

Thu, 03 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Thu, 03 Sep 2026 15:00:00 +0000

Type Values Removed Values Added
Description Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.
Title Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path
Weaknesses CWE-617
References
Metrics cvssV3_1

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

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-09-03T15:10:21.808Z

Reserved: 2026-09-02T17:58:52.743Z

Link: CVE-2026-84971

cve-icon Vulnrichment

Updated: 2026-09-03T15:10:16.072Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-03T15:17:36.547

Modified: 2026-09-03T17:52:05.570

Link: CVE-2026-84971

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T18:00:07Z

Weaknesses