Secuno
ENNL
Book demo

CVE-2026-18691

Mongodb vulnerability

8.8 HIGHEPSS 0.36%
  1. Published11 Aug 2026

Description

An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment.

CVSS 3.1 breakdown

Attack vectorAdjacent
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Mongodb≥ 7.0.0 < 7.0.40 · ≥ 8.0.0 < 8.0.29 · ≥ 8.2.0 ≤ 8.2.12 · ≥ 8.3.0 < 8.3.8

Remediation

Fixed in
Mongodb≥ 7.0.40

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-891778.8
WeenyGenius, a computer lab management system by Howyar Technologies, has a Use of…
CVE-2026-728899.8
Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature…
CVE-2026-728879.8
Net::OAuth::Client versions before 0.32 for Perl allow the service provider to silently…
CVE-2025-241549.1
An out-of-bounds write was addressed with improved input validation. This issue is…
CVE-2024-49959.8
Wapro ERP Desktop is vulnerable to MS SQL protocol downgrade request from a server…
CVE-2024-388839.1
An issue in Horizon Business Services Inc. Caterease 16.0.1.1663 through 24.0.1.2405…

Frequently asked

Is CVE-2026-18691 being actively exploited?

CVE-2026-18691 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.36%.

How severe is CVE-2026-18691?

CVE-2026-18691 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 0.36% probability of exploitation.

Which products are affected by CVE-2026-18691?

Affected products include Mongodb.

How do I fix CVE-2026-18691?

Upgrade affected software to a fixed version, for example Mongodb 7.0.40 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-18691 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.