Description
A vulnerability allowing a low-privileged local user to write arbitrary files with SYSTEM privileges during the installation of Veeam Backup for Microsoft 365, which can lead to privilege escalation or denial of service.
Published: 2026-10-27
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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References
Link Providers
https://www.veeam.com/kb4957 cve-icon cve-icon
History

Wed, 28 Oct 2026 23:30:00 +0100

Type Values Removed Values Added
First Time appeared Veeam
Veeam backup For Microsoft 365
Vendors & Products Veeam
Veeam backup For Microsoft 365

Tue, 27 Oct 2026 19:15:00 +0100

Type Values Removed Values Added
Title Privilege Escalation in Veeam Backup for Microsoft 365 via Installation File Write

Tue, 27 Oct 2026 17:30:00 +0100

Type Values Removed Values Added
Description A vulnerability allowing a low-privileged local user to write arbitrary files with SYSTEM privileges during the installation of Veeam Backup for Microsoft 365, which can lead to privilege escalation or denial of service.
Weaknesses CWE-1386
References
Metrics cvssV4_0

{'score': 4.3, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Veeam Backup For Microsoft 365
cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-10-27T16:16:58.979Z

Reserved: 2025-10-31T15:00:01.447Z

Link: CVE-2025-64394

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-27T17:16:53.867

Modified: 2026-10-28T14:47:07.963

Link: CVE-2025-64394

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T23:12:16Z

Weaknesses