CVE-2026-84966

mediumpriority · track · 22EPSS 0.001 · 4 %ileDEUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.14% (4th) EPSS
CVSS 5.5 · medium
Is it mine?
10 products
Check your exposure
Who says so?
2 sources
cert_bund · nvd

EPSS · scored 2026-10-27

An incorrect numeric type conversion in the BSON document building component of the MongoDB C++ Driver may cause a length value to be interpreted incorrectly. When an application supplies an extremely large, non-terminated field name to the builder, the library may read memory outside the intended buffer and terminate the calling process. No authentication is required, but the calling application must pass the oversized name in a specific form.

01

cvss

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

5.9
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.1–5.9

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 3.6
v3.15.1mediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · cna@mongodb.comexploitability 1.4 · impact 3.6
v4.05.9mediumCVSS:4.0/AV:L/AC:L/AT:P/PR:N/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
v4.02.1lowCVSS:4.0/AV:L/AC:L/AT:P/PR:N/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)
02

ssvc

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

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (10)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-3209MongoDB: Mehrere SchwachstellenDeutsch2026-09-06csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in MongoDB ausnutzen, um einen Denial of Service zu verursachen, Daten zu manipulieren, Informationen offenzulegen oder beliebige Befehle über die MongoDB-Erweiterung für Visual Studio Code auszuführen.

06

sources

Which sources assert this record, and when.

published 2026-09-03modified 2026-09-03
07

references (1) nvd

External citations — patches, advisories, analysis.

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