Cyber Resilience

CVE-2026-69598

Microsoft Windows 10 21H2 ≤ 10.0.19044.7725

Published
08 September 2026
Modified
21 September 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0084 56th percentile
Risk Priority 65 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-69598 is a high-severity Incorrect Calculation of Buffer Size (CWE-131) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Incorrect calculation of buffer size in Windows iSCSI allows an unauthorized attacker to execute code over a network.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20049Shared CWE-131
CVE-2026-53091Shared CWE-131
CVE-2026-2738Shared CWE-131
CVE-2026-42915Shared CWE-131
CVE-2024-39808Shared CWE-131
CVE-2023-52558Shared CWE-131
CVE-2020-17087Shared CWE-131
CVE-2026-1949Shared CWE-131
CVE-2026-22791Shared CWE-131
CVE-2023-45871Shared CWE-131

Affected Assets

microsoft
windows 10 1607
≤ 10.0.14393.9512 · ≤ 10.0.14393.9512
microsoft
windows 10 1809
≤ 10.0.17763.9245 · ≤ 10.0.17763.9245
microsoft
windows 10 21h2
≤ 10.0.19044.7725 · ≤ 10.0.19044.7725 · ≤ 10.0.19044.7725
microsoft
windows 10 22h2
≤ 10.0.19045.7725 · ≤ 10.0.19045.7725 · ≤ 10.0.19045.7725
microsoft
windows 11 23h2
≤ 10.0.22631.7582 · ≤ 10.0.22631.7582
microsoft
windows 11 24h2
≤ 10.0.26100.9445 · ≤ 10.0.26100.9445
microsoft
windows 11 25h2
≤ 10.0.26200.9445 · ≤ 10.0.26200.9445
microsoft
windows 11 26h1
≤ 10.0.28000.2954 · ≤ 10.0.28000.2954
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.9512
+3 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer security testing and code review can discover incorrect buffer-size computations before deployment.

Secure engineering principles directly require correct buffer-size arithmetic and bounds-checked allocation.

Input validation can enforce that supplied lengths or counts used in size calculations are within safe bounds.

Memory-protection mechanisms limit the exploitability of an overflow that results from an incorrect size calculation.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly prevent buffer-size miscalculations via coding standards, reviews, and testing, while fixing this single weakness only partially fulfills the broader control.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure development lifecycle mandates size-checking practices that reduce buffer-size miscalculations.

prevents

Application security requirements can specify buffer-size validation rules.

prevents

Secure architecture principles include safe memory-allocation guidelines.

prevents

Secure coding standards directly require correct buffer-size calculations.

finds

Security testing can detect buffer-size errors before release.

References