CVE-2026-114646

MEDIUM
Published Oct 22, 2026 Modified Oct 23, 2026 CWE-130

Description

A data-validation flaw exists in the BSON handling and binary serialization path of the MongoDB C# Driver. When an application constructs a raw or lazy BSON document object from externally supplied binary data, the driver does not verify that the size quantity declared inside that data matches the amount of data actually provided, and it copies the data onto the wire unchanged. An unauthenticated party who can supply binary content to such an application can thereby cause additional elements to be inserted into, or existing elements to be removed from, the database command the application issues, without needing any database credentials of their own. This can result in unauthorized modification of stored data and disclosure of data outside the intended scope of the application's request, bounded by the database privileges the application itself holds.

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CVSS v3.1 Score

6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0026
Probability of exploitation
0.18%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-130 CWE-130

References

Frequently Asked Questions

What is CVE-2026-114646? +
A data-validation flaw exists in the BSON handling and binary serialization path of the MongoDB C# Driver. When an application constructs a raw or lazy BSON document object from externally supplied binary data, the driver does not verify that the size quantity declared inside that data matches the amount of data actually provided, and it copies the data onto the wire unchanged. An unauthenticated party who can supply binary content to such an application can thereby cause additional elements to be inserted into, or existing elements to be removed from, the database command the application issues, without needing any database credentials of their own. This can result in unauthorized modification of stored data and disclosure of data outside the intended scope of the application's request, bounded by the database privileges the application itself holds. It has a CVSS v3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2026-114646? +
CVE-2026-114646 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-114646? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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