Medium 5.7Published Oct 8, 2026

CVE-2026-106431One-byte heap buffer overflow in BSON bulk document writer in MongoDB C Driver

Updated under an hour ago (2026-10-19 08:30 UTC)

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It affects MongoDB C Driver. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for MongoDB C Driver

Exploited in the last 30 days

An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process. Reaching this issue requires the application to use the BSON bulk-writer API and produce a precise cumulative document size.

CVSS: 5.7 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Weakness (CWE): CWE-787
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: mongodb
NVD analysis: Awaiting Analysis
Record last updated: Oct 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

MongoDB C Driver mongodb:c_driver (from the name)	from 0.5.0 before 1.30.13; from 2.0.0 before 2.5.6	CNA record

References

https://jira.mongodb.org/browse/CDRIVER-6418

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.