CVE-2026-81530: MongoDB C# Driver

Medium severity, CVSS 5.6. EPSS: 0.1% chance of exploitation in the next 30 days.

A weakness in the client-side encryption configuration surface of the MongoDB C# Driver causes sensitive key-management credential material supplied by the application to be reproduced verbatim in the driver's human-readable diagnostic representation of its client settings, instead of being masked as other secret fields are. A party able to read the application's logs, diagnostic output, or a process memory dump may thereby recover the plaintext credentials and use them to decrypt protected field data.

Affected products

• MongoDB C# Driver: from 2.10.0, before 3.11.1 (fixed in 3.11.1)

Published 2026-08-27. Last modified 2026-09-29.