Improper input validation in MongoDB C Driver
CVE-2026-6231
The bson_validate function may return early on specific inputs and incorrectly report success. This behavior could result in skipping validation for BSON data, allowing malformed or invalid UTF-8 sequences to bypass validation and be processed incorrectly. The issue may affect applications that rely on these functions to validate untrusted BSON data before further processing. This issue affects MongoDB C Driver versions prior to 1.30.5, MongoDB C Driver version 2.0.0 and MongoDB C Driver version 2.0.1
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- MongoDB C Driver
- MongoDB Inc. C Driver — versions 1.0, 2.0
Weakness classification (CWE)
References
- jira.mongodb.org/browse/CDRIVER-6017 (issue-tracking, Patch, Issue Tracking)
Frequently asked questions
- What is CVE-2026-6231?
- CVE-2026-6231 is a medium-severity vulnerability in MongoDB C Driver, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2026-04-13.
- How severe is CVE-2026-6231?
- Medium severity. CVSS v3 base score is 4.3 out of 10.