Windows iSCSI: Heap-based buffer overflow allows local privilege escalation

Summary

A heap-based buffer overflow (CWE-122) in the Windows iSCSI component allows an authorized local attacker to elevate privileges. The CVSS base score is 7.8 (High), with high impact on confidentiality, integrity and availability. The attack is not reachable directly from the internet. It requires a low-privileged local account, so it is mainly a risk after an attacker has already gained a foothold on the system.

Affected

• Windows 10 Version 1607 (builds 10.0.14393.0 before 10.0.14393.9688)
• Windows 10 Version 1809 (builds 10.0.17763.0 before 10.0.17763.9487)
• Windows 10 Version 21H2 (builds 10.0.19044.0 before 10.0.19044.7846)
• Windows 10 Version 22H2 (builds 10.0.19045.0 before 10.0.19045.7846)
• Windows 11 Version 23H2 (builds 10.0.22631.0 before 10.0.22631.7711)
• Windows 11 Version 24H2 (builds 10.0.26100.0 before 10.0.26100.9974)
• Windows 11 Version 25H2 (builds 10.0.26200.0 before 10.0.26200.9974)
• Windows 11 Version 26H1 (builds 10.0.28000.0 before 10.0.28000.3501)
• Windows 11 Version 26H2 (builds 10.0.26300.0 before 10.0.26300.9974)
• Windows Server 2016, including Server Core (builds 10.0.14393.0 before 10.0.14393.9688)
• Windows Server 2019, including Server Core (builds 10.0.17763.0 before 10.0.17763.9487)
• Windows Server 2022 (builds 10.0.20348.0 before 10.0.20348.5870)
• Full product list not yet verified on the MSRC advisory

Fixed in

Microsoft's November 2026 security update (Patch Tuesday, 10 November 2026). Install the cumulative update for your build and confirm that the installed build is at or above the fixed build listed above. KB numbers: check the MSRC advisory.

Workaround

Unknown.

Exploitation

• Not known to be exploited in the wild at the time of writing.
• No public proof of concept found.
• Not listed in CISA KEV at the time of writing.
• CVSS exploit code maturity is 'Unproven' (E:U).

Our recommendation

• Apply the November 2026 security update on all affected systems, prioritising servers and multi-user systems (such as file and terminal servers) that use iSCSI.
• Confirm iSCSI use per system and check the installed build against the fixed build.
• Check the MSRC advisory for the full product list, KB numbers and any mitigation.
• Restrict local logon to trusted accounts and monitor for privilege escalation.
• Recheck NVD and CISA KEV in the coming weeks, as the CVE was published recently.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-95898 msrc.microsoft.com
• CVE Record: CVE-2026-95898 www.cve.org
• KB5131096 (Windows 10 21H2, November 2026) senserva.com
• Strix AI: CVE-2026-95898 (third-party, unverified product list) 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, 03:04.