Is CVE-2026-21666 actively exploited?

CVE-2026-21666 has no public evidence of in-the-wild exploitation as of 2026-03-12.

What is the CVSS score for CVE-2026-21666?

CVE-2026-21666 has a CVSS score of 9.9 (CRITICAL severity). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

How do I patch CVE-2026-21666?

Vendor patch guidance is linked from the references on this page. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-21666.

Which products are affected by CVE-2026-21666?

Affected products for CVE-2026-21666 are listed on this page once vendor data becomes available.

Fix CVE-2026-21666 - CRITICAL Vulnerability

Description

A vulnerability allowing an authenticated domain user to perform remote code execution (RCE) on the Backup Server.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: low
User Action: none
Scope: changed
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-284

Metadata

Primary Vendor: UNKNOWN
Published: 3/12/2026
Last Modified: 3/12/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

No affected products information available.

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-21666. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-21666

View on NIST NVD

CVE-2026-21666 vulnerability