Microsoft Windows iSCSI: Information disclosure via out-of-bounds read
Summary
An out-of-bounds read in the Windows iSCSI component allows an authorized attacker to read memory contents over the network, which leads to information disclosure. The attack requires network access, low privileges and user interaction, and the impact is limited to confidentiality. The flaw is not a remote code execution vulnerability. Microsoft released fixes on 10 November 2026.
Affected
- Windows 10 Version 1607 and Windows Server 2016 (including Server Core): 10.0.14393.0 to < 10.0.14393.9688
- Windows 10 Version 1809 and Windows Server 2019 (including Server Core): 10.0.17763.0 to < 10.0.17763.9487
- Windows 10 Version 21H2: 10.0.19044.0 to < 10.0.19044.7846
- Windows 10 Version 22H2: 10.0.19045.0 to < 10.0.19045.7846
- Windows 11 Version 23H2: 10.0.22631.0 to < 10.0.22631.7711
- Windows 11 Version 24H2: 10.0.26100.0 to < 10.0.26100.9974
- Windows 11 Version 25H2: 10.0.26200.0 to < 10.0.26200.9974
- Windows 11 Version 26H1: 10.0.28000.0 to < 10.0.28000.3501
- Windows 11 Version 26H2: 10.0.26300.0 to < 10.0.26300.9974
- Windows Server 2022: 10.0.20348.0 to < 10.0.20348.5870
Fixed in
- Fixed builds according to the CNA record (upper bound of each affected range):
- Windows 10 1607 and Server 2016: 10.0.14393.9688
- Windows 10 1809 and Server 2019: 10.0.17763.9487
- Windows 10 21H2: 10.0.19044.7846
- Windows 10 22H2: 10.0.19045.7846
- Windows 11 23H2: 10.0.22631.7711
- Windows 11 24H2: 10.0.26100.9974
- Windows 11 25H2: 10.0.26200.9974
- Windows 11 26H1: 10.0.28000.3501
- Windows 11 26H2: 10.0.26300.9974
- Windows Server 2022: 10.0.20348.5870
- KB article numbers: Unknown. Verify the builds against the MSRC advisory.
Workaround
Unknown. No vendor workaround has been documented.
- If patching is not possible, restrict which hosts can reach iSCSI ports and limit who holds valid credentials. This is a general recommendation, not a documented Microsoft mitigation.
Exploitation
- No known exploitation in the wild.
- Rapid7 rates it as "Exploitation Less Likely".
- CISA SSVC: exploitation none, not automatable.
- VulDB reports that no exploit is available.
Our recommendation
- Inventory Windows hosts that run iSCSI initiators or targets, for example file or storage servers.
- Install the November 2026 security update on affected systems, in the same batch as the more critical iSCSI remote code execution CVEs.
- Restrict iSCSI access to trusted hosts and networks.
- Re-check the NVD entry and CISA KEV once NVD analysis is complete.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Windows iSCSI
- 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, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide (MSRC) msrc.microsoft.com
- Rapid7 November 2026 Patch Tuesday www.rapid7.com
- BleepingComputer November 2026 Patch Tuesday www.bleepingcomputer.com
- VulDB entry vuldb.com
- Strix CVE-2026-88231 (third-party aggregator) 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, 15:45.
Original description (NVD)
Out-of-bounds read in Windows iSCSI allows an authorized attacker to disclose information over a network.
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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