CVE-2026-81530 — MongoDB C# Driver

What is CVE-2026-81530?

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.

The record classifies CVE-2026-81530 under weakness class CWE-532. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 39 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 5.6 — MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
CVSS v4.0 base score: 6.8
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
EPSS (FIRST): 0.0% probability of exploitation in the next 30 days, higher than 2.1% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 2.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-08-27, last modified 2026-08-28

Is CVE-2026-81530 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

Affected products and versions

MongoDB: C# Driver

How to fix CVE-2026-81530

No vendor patch reference has been recorded for CVE-2026-81530 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-81530

No threat campaign in the Threadlinqs corpus currently references CVE-2026-81530, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-08-30. This product uses the NVD API but is not endorsed or certified by the NVD.