Vulnerability in MongoDB Bi Connector

CVE-2026-81517

An unauthenticated party able to reach the port of a MongoDB Connector for BI (mongosqld) instance may generate enough routine connection log activity to exhaust the storage backing the configured log path. When a log write or log rotation operation subsequently fails, the resulting error is not handled and the shared mongosqld process ends, ending service for all connected SQL clients. The process continues to end on startup until an operator restores available storage, and the diagnostic message explaining the condition is not recorded.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (38.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-81517: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81517?
CVE-2026-81517 is a high-severity vulnerability in MongoDB Bi Connector, classified under CWE-248. CVSS score: 7.5/10. Published 2026-08-28.
How severe is CVE-2026-81517?
High severity. CVSS v3 base score is 7.5 out of 10.