CVE-2026-84971

mediumpriority · track · 0EPSS 0.003 · 18 %ileDEUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.26% (18th) EPSS

CVSS 6.5 · medium

Is it mine?

3 products

Check your exposure

Who says so?

2 sources

cert_bund · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.9–7.1

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · cna@mongodb.comexploitability 2.8 · impact 3.6

v4.07.1highCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · cna@mongodb.com

v4.04.9mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-617US

affected products (3)

Products and version ranges known to be affected.

Open Source MongoDB libmongocrypt <1.20.4all versionscert_bundDE
Open Source MongoDB≤ libmongocrypt <1.20.4cert_bundDE
mongodb libmongocrypt1.7.0 → 1.20.4nvdUScpe:2.3:a:mongodb:libmongocrypt:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3182MongoDB: Mehrere SchwachstellenDeutsch2026-09-03csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in verschiedenen MongoDB Treibern und einer Bibliothek ausnutzen, um Daten zu manipulieren oder offenzulegen, sowie um einen Denial of Service Zustand herbeizuführen.

sources

Which sources assert this record, and when.

cert_bund nvd NVD CVE.org MITRE

published 2026-09-03modified 2026-09-03

references (1) nvd

External citations — patches, advisories, analysis.

https://jira.mongodb.org/browse/MONGOCRYPT-971

scry

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