Cyber Resilience

CVE-2026-32155

Memory Safety in Microsoft Windows 10 21H2 ≤ 10.0.19044.7184

Memory Safety
Published
14 April 2026
Modified
21 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0026 17th percentile
Risk Priority 56 floored blend · peak EPSS

Summary

CVE-2026-32155 is a high-severity Use After Free (CWE-416) 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 Client Execution (T1203); ranked at the 17th 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 SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-32155 is a use-after-free vulnerability (CWE-416) in the Desktop Window Manager, a core Windows component responsible for compositing windows and rendering the desktop environment. Published on 2026-04-14, it carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact despite requiring local access.

The vulnerability can be exploited by an authorized local attacker possessing low privileges. Exploitation involves low-complexity techniques with no user interaction needed, enabling the attacker to trigger the use-after-free condition in Desktop Window Manager. Successful exploitation allows privilege escalation, granting high impacts on confidentiality, integrity, and availability, such as executing code at elevated privilege levels.

Microsoft's advisory provides guidance on mitigation through the update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32155.

EU & UK References

Vulnerability Data

Use after free in Desktop Window Manager allows an authorized attacker to elevate privileges locally.

CWE(s)
CWE-416

Related Threats

MITRE ATT&CK Enterprise Techniques

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
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 →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-21242Same product: Microsoft Windows 10 21H2
CVE-2026-20871Same product: Microsoft Windows 10 21H2
CVE-2025-55686Same product: Microsoft Windows 10 21H2
CVE-2026-20842Same product: Microsoft Windows 10 21H2
CVE-2025-55331Same product: Microsoft Windows 10 21H2
CVE-2025-55689Same product: Microsoft Windows 10 21H2
CVE-2025-55685Same product: Microsoft Windows 10 21H2
CVE-2026-26132Same product: Microsoft Windows 10 21H2
CVE-2025-62221Same product: Microsoft Windows 10 21H2
CVE-2026-20923Same product: Microsoft Windows 10 21H2

Affected Assets

microsoft
windows 10 21h2
≤ 10.0.19044.7184 · ≤ 10.0.19044.7184 · ≤ 10.0.19044.7184
microsoft
windows 10 22h2
≤ 10.0.19045.7184 · ≤ 10.0.19045.7184 · ≤ 10.0.19045.7184
microsoft
windows 11 23h2
≤ 10.0.22631.6936 · ≤ 10.0.22631.6936
microsoft
windows 11 24h2
≤ 10.0.26100.8246 · ≤ 10.0.26100.8246
microsoft
windows 11 25h2
≤ 10.0.26200.8246 · ≤ 10.0.26200.8246
microsoft
windows server 2022
≤ 10.0.20348.5020
microsoft
windows server 2022 23h2
≤ 10.0.25398.2274
microsoft
windows server 2025
≤ 10.0.26100.32690

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

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

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover use-after-free bugs through dynamic analysis or fuzzing.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require memory-safe constructs or languages that structurally avoid introducing use-after-free.

SC-39 Process Isolation partial match

Process isolation confines the blast radius of use-after-free memory corruption to a single execution domain.

SI-16 Memory Protection partial match

Memory protection controls limit exploitation impact by blocking unauthorized code execution from dangling pointers.

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
finds

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.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 9 (1 rule)
  • V-257794 RHEL 9 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416

References