8.7

CVE-2026-81520: mongodb bi_connector

CVSS: 8.7v4.0HighAnalyzed
Published 28-08-2026Last modified 31-08-2026
Open JSON

Vulnerability summary

CVE-2026-81520 is a high (CVSS 8.7) vulnerability in mongodb bi_connector. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.7% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.18 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 28-08-2026
    PublishedVulnerability first disclosed.
  2. 31-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.18 pp

From 0.24% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mongodb1 product

1 vendor · 1 product

References

1 links