Detections
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CBL Mariner 2.0 Security Update: CBL-Mariner Releases (CVE-2026-33413)

high Nessus Plugin ID 304498

Synopsis

The remote CBL Mariner host is missing one or more security updates.

Description

The version of CBL-Mariner Releases installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2026-33413 advisory.

 - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42, 3.5.28, and 3.6.9, unauthorized users May bypass authentication or authorization checks and call certain etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch, audit, and recovery workflows. Kubernetes does not rely on etcd's built-in authentication and authorization. Instead, the API server handles authentication and authorization itself, so typical Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice.
 Restrict network access to etcd server ports so only trusted components can connect and/or require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
 (CVE-2026-33413)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 304498

File Name: mariner_CVE-2026-33413.nasl

Version: 1.1

Type: Local

Published: 4/1/2026

Updated: 4/1/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-33413

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.8

Threat Score: 6.8

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: p-cpe:/a:microsoft:cbl-mariner:etcd, x-cpe:/o:microsoft:cbl-mariner

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/CBLMariner/release, Host/CBLMariner/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 3/10/2026

Vulnerability Publication Date: 3/10/2026

Reference Information

CVE: CVE-2026-33413