Cyber Resilience

CVE-2026-49797

Memory Safety in Microsoft Windows 10 21H2 ≤ 10.0.19044.7548

Published
14 July 2026
Modified
22 July 2026
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0036 29th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-49797 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-16 (Memory Protection) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Heap-based buffer overflow in Windows NTFS allows an unauthorized attacker to execute code locally.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Local heap buffer overflow in NTFS kernel driver directly enables exploitation for privilege escalation to achieve code execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-57096Same product: Microsoft Windows 10 1607
CVE-2026-54992Same product: Microsoft Windows 10 1607
CVE-2026-56175Same product: Microsoft Windows 10 1607
CVE-2026-50461Same product: Microsoft Windows 10 1607
CVE-2026-50489Same product: Microsoft Windows 10 1607
CVE-2026-50386Same product: Microsoft Windows 10 1607
CVE-2026-54987Same product: Microsoft Windows 10 1607
CVE-2026-49184Same product: Microsoft Windows 10 1607
CVE-2026-50330Same product: Microsoft Windows 10 1607
CVE-2026-50309Same product: Microsoft Windows 10 1607

Affected Assets

microsoft
windows 10 1607
≤ 10.0.14393.9339 · ≤ 10.0.14393.9339
microsoft
windows 10 1809
≤ 10.0.17763.9020 · ≤ 10.0.17763.9020
microsoft
windows 10 21h2
≤ 10.0.19044.7548 · ≤ 10.0.19044.7548 · ≤ 10.0.19044.7548
microsoft
windows 10 22h2
≤ 10.0.19045.7548 · ≤ 10.0.19045.7548 · ≤ 10.0.19045.7548
microsoft
windows 11 24h2
≤ 10.0.26100.8875 · ≤ 10.0.26100.8875
microsoft
windows 11 25h2
≤ 10.0.26200.8875 · ≤ 10.0.26200.8875
microsoft
windows 11 26h1
≤ 10.0.28000.2269 · ≤ 10.0.28000.2525
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.9339
microsoft
windows server 2019
≤ 10.0.17763.9020
+2 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly implements memory protections (e.g., heap integrity checks, ASLR/DEP) that block exploitation of the heap buffer overflow in ntfs.sys.

prevent

Requires timely patching of the NTFS driver flaw to eliminate the buffer-overflow vulnerability before local exploitation occurs.

prevent

Enforces least privilege so that even a local attacker who triggers the overflow has minimal rights to achieve meaningful code execution.

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 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

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.

detects

Security testing in development and acceptance can detect heap overflows before release.

prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

none

Change management ensures controlled deployment of fixes for discovered heap-overflow vulnerabilities.

References