Cyber Resilience

CVE-2026-54995

Memory Safety in Microsoft Windows 10 21H2 ≤ 10.0.19044.7548

Memory Safety
Published
14 July 2026
Modified
20 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0059 45th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-54995 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 45th 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

Use after free in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over a network.

CWE(s)
CWE-416

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Why these techniques?

Use-after-free in RMCAST driver enables remote code execution over network without auth, directly facilitating T1190 (public-facing network protocol exploitation) and T1210 (remote service exploitation).

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

CVEs Like This One

CVE-2026-45599Same product: Microsoft Windows 10 1607
CVE-2026-50505Same product: Microsoft Windows 10 1607
CVE-2026-50694Same product: Microsoft Windows 10 1607
CVE-2026-57089Same product: Microsoft Windows 10 1607
CVE-2026-56649Same product: Microsoft Windows 10 1607
CVE-2026-50439Same product: Microsoft Windows 10 1607
CVE-2026-45635Same product: Microsoft Windows 10 1607
CVE-2026-40415Same product: Microsoft Windows 10 1809
CVE-2026-23669Same product: Microsoft Windows 10 1607
CVE-2026-50312Same 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
≤ 10.0.28000.2525 · ≤ 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)
  • SI-2 Flaw Remediation
  • SI-16 Memory Protection
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Directly requires timely remediation of the use-after-free flaw in RMCAST to eliminate the remote code execution path.

SI-16 Memory Protection good match
prevent

Implements memory protections that block exploitation of use-after-free conditions leading to unauthorized code execution.

SC-7 Boundary Protection partial match
prevent

Boundary protection restricts network access to the vulnerable RMCAST driver, reducing the attack surface for remote exploitation.

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 mostly match
prevents

Secure SDLC practices directly incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
prevents

Routine patching removes known use-after-free instances after they have been introduced in released software.

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.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing in development can detect use-after-free bugs before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates memory-safety practices that reduce use-after-free defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify memory-management rules that mitigate use-after-free.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include memory-safety design choices that limit use-after-free exposure.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe avoidance of use-after-free patterns.

A.8.32 Change management partial match
prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

References