Linux Distros Unpatched Vulnerability : CVE-2026-21723

medium Nessus Plugin ID 329649

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- The alertmanager templates test endpoint (/api/alertmanager/grafana/config/api/v1/templates/test) can execute templates with no memory limits. Mass-executing templates in a short period causes OOM and crashes the Grafana service. The endpoint requires very low privileges and is exploitable with anonymous access enabled. (CVE-2026-21723)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-21723

Plugin Details

Severity: Medium

ID: 329649

File Name: unpatched_CVE_2026_21723.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 7/25/2026

Updated: 7/25/2026

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.76

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

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

CVSS Score Source: CVE-2026-21723

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.9

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

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

Vulnerability Information

CPE: cpe:/o:centos:centos:8, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:centos:centos:grafana-azure-monitor, p-cpe:/a:centos:centos:grafana-cloudwatch, p-cpe:/a:centos:centos:grafana-elasticsearch, p-cpe:/a:centos:centos:grafana-graphite, p-cpe:/a:centos:centos:grafana-influxdb, p-cpe:/a:centos:centos:grafana-loki, p-cpe:/a:centos:centos:grafana-mssql, p-cpe:/a:centos:centos:grafana-mysql, p-cpe:/a:centos:centos:grafana-opentsdb, p-cpe:/a:centos:centos:grafana-postgres, p-cpe:/a:centos:centos:grafana-prometheus, p-cpe:/a:centos:centos:grafana-selinux, p-cpe:/a:centos:centos:grafana-stackdriver, p-cpe:/a:centos:centos:grafana, p-cpe:/a:redhat:enterprise_linux:grafana-azure-monitor, p-cpe:/a:redhat:enterprise_linux:grafana-cloudwatch, p-cpe:/a:redhat:enterprise_linux:grafana-elasticsearch, p-cpe:/a:redhat:enterprise_linux:grafana-graphite, p-cpe:/a:redhat:enterprise_linux:grafana-influxdb, p-cpe:/a:redhat:enterprise_linux:grafana-loki, p-cpe:/a:redhat:enterprise_linux:grafana-mssql, p-cpe:/a:redhat:enterprise_linux:grafana-mysql, p-cpe:/a:redhat:enterprise_linux:grafana-opentsdb, p-cpe:/a:redhat:enterprise_linux:grafana-postgres, p-cpe:/a:redhat:enterprise_linux:grafana-prometheus, p-cpe:/a:redhat:enterprise_linux:grafana-selinux, p-cpe:/a:redhat:enterprise_linux:grafana-stackdriver, p-cpe:/a:redhat:enterprise_linux:grafana

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/23/2026

Reference Information

CVE: CVE-2026-21723