What is the CVSS score of CVE-2026-21672?

CVE-2026-21672 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

How to fix or mitigate CVE-2026-21672?

Within 24 hours: Inventory all Windows-based Veeam Backup & Replication servers and restrict local administrative access to essential personnel only. Within 7 days: Implement enhanced monitoring and logging on affected Veeam servers, review access logs for suspicious privilege escalation attempts, and apply compensating controls listed below. Within 30 days: Prepare for immediate patching upon vendor release and conduct a full security audit of Veeam infrastructure.

Microsoft CVE-2026-21672

HIGH

Insertion of Sensitive Information into Externally-Accessible File (CWE-538)

2026-03-12 support@hackerone.com

Privilege Escalation Microsoft

8.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate as low-privilege local user
Delivery

Exploit unquoted service path in Veeam process
Exploit

Place malicious executable in path
Execution

Service restart triggers arbitrary code execution
Impact

Attain system privileges

Vulnerability Assessment

Weakness	CWE CWE-538 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V14 - Data Protection Sensitive file access control
Exploitation Conditions	Low-privilege local user account on Windows system running Veeam Backup & Replication with vulnerable service configuration using unquoted executable paths in service registry entries.
Impact	CVSS 8.8 (HIGH). Attack vector: Local. Complexity: Low. Privileges required: Low. User interaction: None. Exploitable via local access.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Local privilege escalation in Veeam Backup & Replication on Windows enables authenticated users to gain system-level access without user interaction. An attacker with local account credentials can exploit this vulnerability to achieve complete control over the backup infrastructure, including reading, modifying, or deleting backups. No patch is currently available for this high-severity issue affecting backup administrators and organizations relying on Veeam for data protection.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 19:57 CVSS 8.8

A vulnerability allowing local privilege escalation on Windows-based Veeam Backup & Replication servers. [CVSS 8.8 HIGH]

RemediationAI

Monitor vendor advisories for a patch.

Affected ProductsAI

A vulnerability allowing local privilege escalation on Windows-based Veeam Backup & Replication servers.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

A vulnerability allowing local privilege escalation on Windows-based Veeam Backup & Replication servers.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

DescriptionCVE.org

A vulnerability allowing local privilege escalation on Windows-based Veeam Backup & Replication servers.

Executive ViewAI

Why It Matters

A high-severity local privilege escalation vulnerability (CVE-2026-21672) affects Windows-based Veeam Backup & Replication servers, allowing authenticated users to gain system-level access. This directly threatens backup infrastructure security and could enable attackers to compromise, exfiltrate, or destroy critical backup data that organizations depend on for recovery operations.

Business Impact: High

Compensating Controls

Implement strict access controls restricting local logon privileges to Veeam servers—disable interactive login for service accounts. 2) Enable Windows Event Logging (Security and System logs) with real-time alerting for privilege escalation attempts (Event IDs 4672, 4673). 3) Deploy endpoint detection and response (EDR) tools on Veeam servers to monitor for suspicious process execution and privilege escalation patterns. 4) Isolate Veeam Backup & Replication servers on a dedicated, segmented network with strict ingress/egress firewall rules. 5) Disable unnecessary local services and features on affected servers. 6) Apply principle of least privilege to all service accounts and API tokens used by Veeam. Monitor vendor advisories closely for patch availability.

Threat Intelligence Overview

EPSS Score

0.1%

Top 84% exploitable

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.1%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Small

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +44

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.