Cyber Resilience

CVE-2026-58626

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 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0085 55th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-58626 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked in the top 45% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-7 (Boundary 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 Windows Remote Desktop Services allows an authorized attacker to execute code over a network.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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

Use-after-free in RDP service directly enables remote code execution via exploitation of the remote service.

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

CVEs Like This One

CVE-2026-50505Same product: Microsoft Windows 10 21H2
CVE-2026-57089Same product: Microsoft Windows 10 21H2
CVE-2026-50459Same product: Microsoft Windows 10 21H2
CVE-2026-40415Same product: Microsoft Windows 10 21H2
CVE-2026-45640Same product: Microsoft Windows 10 21H2
CVE-2026-50486Same product: Microsoft Windows 10 21H2
CVE-2026-50326Same product: Microsoft Windows 10 21H2
CVE-2026-50293Same product: Microsoft Windows 10 21H2
CVE-2026-50425Same product: Microsoft Windows 10 21H2
CVE-2026-58608Same product: Microsoft Windows 10 21H2

Affected Assets

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 · ≤ 10.0.28000.2269
microsoft
windows server 2022
≤ 10.0.20348.5386
microsoft
windows server 2025
≤ 10.0.26100.33158

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SC-7 Boundary Protection
  • AC-6 Least Privilege
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

prevent

Directly requires timely remediation of the use-after-free flaw in Remote Desktop Services before an authorized network attacker can exploit it for RCE.

prevent

Restricts network exposure of Remote Desktop Services, blocking the attack vector even for authorized users on untrusted networks.

prevent

Limits privileges of authorized Remote Desktop users so that successful UAF exploitation yields minimal system impact.

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.

detects

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

prevents

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

prevents

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

prevents

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

prevents

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

prevents

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

References