Microsoft Azure File Sync: Local privilege escalation via incorrect permissions
Summary
Microsoft Azure File Sync contains an incorrect permission assignment for a critical resource (CWE-732). An authorized local user with low privileges can exploit it to gain higher privileges on the affected host. Exploitation requires local access and a high-complexity condition, and the vulnerability is not reachable from the internet.
Affected
- Microsoft Azure File Sync 23.1.0.0 to below 23.2 (according to CNA data; not verified against MSRC)
- Microsoft Azure File Sync 1.0.0 to below 23.2 (according to CNA data; not verified against MSRC)
- Microsoft Azure File Sync v22 1.0.0.0 to below 23.2 (according to CNA data; not verified against MSRC)
Fixed in
Unknown. Check the MSRC advisory for the fixed agent version and KB number.
Workaround
Unknown. No vendor workaround was found. General hardening: limit local interactive logons on sync servers and review NTFS permissions on sync-related paths (not Microsoft guidance).
Exploitation
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
- Rapid7 rates it 'Exploitation Less Likely' and reports no public disclosure
- No public proof of concept found
- Not listed in CISA KEV according to a third-party aggregator (not verified directly)
Our recommendation
- Check the MSRC advisory for the fixed agent version and KB, and confirm the affected range
- Patch Azure File Sync servers in the next regular maintenance window, sooner if local access by untrusted users is a realistic concern
- Restrict local interactive logons on sync servers and review NTFS permissions on sync paths until patched
- Monitor for unexpected privilege changes on file servers and recheck CISA KEV after publication
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-118288 msrc.microsoft.com
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- Strix: CVE-2026-118288 (third-party aggregator) www.strix.ai
- Azure File Sync release notes github.com
- Microsoft Update Catalog: Azure File Sync www.catalog.update.microsoft.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 08:54.
Original description (NVD)
Incorrect permission assignment for critical resource in Azure File Sync allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.