Microsoft Windows Server FSRM: Elevation of privilege via untrusted pointer dereference
Summary
The Windows File Server Resource Management Service (FSRM), a component of Windows Server, contains an untrusted pointer dereference vulnerability (CWE-822). An unauthorized attacker with physical access to the vulnerable component can elevate privileges on the system. The vulnerability is not reachable over the network, and no exploitation is known.
Affected
- Windows Server 2016 (including Server Core): 10.0.14393.0 before 10.0.14393.9688
- Windows Server 2019 (including Server Core): 10.0.17763.0 before 10.0.17763.9487
- Windows Server 2022: 10.0.20348.0 before 10.0.20348.5870 (secondary source, verify on MSRC)
- Windows Server 2025 (including Server Core): 10.0.26100.0 before 10.0.26100.33822 (secondary source, verify on MSRC)
- Windows client versions: Unknown.
Fixed in
- Security updates from November 2026 for the affected Windows Server editions. KB numbers: Unknown; check the MSRC page for each edition.
Workaround
- Unknown whether a Microsoft workaround exists.
- Restrict physical access to servers and storage hardware until patched.
Exploitation
- Not known to be exploited.
- No public proof of concept found.
- Not listed in CISA KEV (per Strix).
- Rapid7 rates exploitation as less likely.
Our recommendation
- Install the November 2026 security updates on all Windows Server systems running FSRM, prioritizing the affected editions listed above.
- Verify the fixed build numbers on the MSRC page for each edition.
- Ensure file servers are located in locked rooms with restricted access.
- Review the other FSRM fixes released in the same update together with this one.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows File Server Resource Management Service
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131090, KB5131080, KB5131077
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-108416 msrc.microsoft.com
- CVE Record CVE-2026-108416 www.cve.org
- Rapid7 Patch Tuesday November 2026 www.rapid7.com
- BleepingComputer: Microsoft November 2026 Patch Tuesday www.bleepingcomputer.com
- Strix: CVE-2026-108416 www.strix.ai
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, 10:43.
Original description (NVD)
Untrusted pointer dereference in Windows File Server Resource Management Service allows an unauthorized attacker to elevate privileges with a physical attack.
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.
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