6.2

CVE-2026-84970: mongodb c_driver

CVSS: 6.2v3.1MediumAnalyzed
AliasesDEBIAN-CVE-2026-84970UBUNTU-CVE-2026-84970
Published 03-09-2026Last modified 03-09-2026
Open JSON

Vulnerability summary

CVE-2026-84970 is a medium (CVSS 6.2) vulnerability in mongodb c_driver. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.9% of scored vulnerabilities.

Overall risk
25/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.2/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.12%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 03-09-2026
    PublishedVulnerability first disclosed.
  2. 03-09-2026
    Last modifiedVulnerability information updated.

Description

A numeric truncation weakness exists in the JSON parsing component of the MongoDB C++ Driver's BSON library. An actor who controls the text that an embedding application hands to the library's public JSON parsing interface, when that text is very large, can cause the library to read memory beyond the supplied buffer and return it to the caller, to silently accept only part of the input as a complete document, or to terminate the process. No MongoDB server, credentials, or non-default configuration is required; the effect is confined to the process that uses the library.

CVSS metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

+0.04 pp

From 0.09% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.12%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • mongo-cxx-driver< 4.5.2-1
Mongodb1 product
Ubuntu1 product
  • mongo-cxx-driverAll versions (No fix recorded)

3 vendors · 3 products

References

4 links