---
id: CVE-2026-81520
title: >-
  A network-reachable client that has not yet authenticated can hold a MongoDB
  Connector for BI authentication session open indefinitely by beginning a
  SASL-based login exchange and then declining to complete it
summary: >-
  A network-reachable client that has not yet authenticated can hold a MongoDB
  Connector for BI authentication session open indefinitely by beginning a
  SASL-based login exchange and then declining to complete it. Because the
  negotiation lo…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1088
vendor: mongodb
product: bi_connector
affected:
  - bi_connector < 2.14.31
patched:
  - bi_connector 2.14.31
published: '2026-08-28'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T19:14:21.290'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81520'
references:
  - url: 'https://www.mongodb.com/docs/bi-connector/current/release-notes/'
    label: cna@mongodb.com
tags:
  - nvd
epss: 0.00419
epssPercentile: 0.33698
ingestedAt: '2026-09-29T19:44:04.122Z'
---

## Overview

A network-reachable client that has not yet authenticated can hold a MongoDB Connector for BI authentication session open indefinitely by beginning a SASL-based login exchange and then declining to complete it. Because the negotiation loop had no overall time bound and the read from the client had no deadline, each such session retains a worker, a client connection slot, and its associated backend database connections until the process is restarted. Repeated use of this behavior can consume the configured connection capacity and prevent legitimate users from establishing new sessions.

## Affected

- `bi_connector < 2.14.31`

## Remediation

Upgrade past the affected range:

- `bi_connector 2.14.31`