What is the CVSS score of CVE-2026-21671?

CVE-2026-21671 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

Which versions of Veeam Backup Replication are affected by CVE-2026-21671?

A critical vulnerability in Veeam Backup & Replication allows authenticated Backup Administrators to execute arbitrary code on HA-deployed systems, potentially compromising backup infrastructure and…

How to fix or mitigate CVE-2026-21671?

Within 24 hours: Inventory all Veeam Backup & Replication HA deployments and audit Backup Administrator role assignments, revoking unnecessary access. Within 7 days: Implement network segmentation to restrict backup infrastructure access and enable enhanced logging on backup servers. Within 30 days: Contact Veeam for patch availability timeline; evaluate air-gapping critical backup systems or migrating to non-HA deployments if patch delay extends beyond 30 days.

Veeam Backup Replication CVE-2026-21671

CRITICAL

Code Injection (CWE-94)

2026-03-12 support@hackerone.com

RCE Code Injection Veeam Backup Replication

9.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.1 CRITICAL

AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 19:57 vuln.today

CVE Published

Mar 12, 2026 - 15:16 nvd

CRITICAL 9.1

DescriptionCVE.org

A vulnerability allowing an authenticated user with the Backup Administrator role to perform remote code execution (RCE) in high availability (HA) deployments of Veeam Backup & Replication.

AnalysisAI

Veeam Backup & Replication allows Backup Administrators to achieve RCE in high-availability deployments. While requiring admin-level access, the scope change to the HA infrastructure makes this critical for organizations running Veeam in HA mode.

Technical ContextAI

In high-availability configurations, a user with the Backup Administrator role can exploit insufficient access controls to execute code beyond the Veeam application boundary (S:C). The HA deployment model may expand the blast radius to multiple Veeam nodes.

RemediationAI

Apply Veeam patches. Implement least-privilege for Backup Administrator roles. Monitor admin actions in HA environments. Segment HA communication channels.