Cyber Resilience

CVE-2026-33824

Memory Safety in Microsoft Windows 10 21H2 ≤ 10.0.19044.7184

CISA KEVActive ExploitationEUVD ExploitedMemory Safety
Published
14 April 2026
Modified
19 August 2026
KEV Added
18 August 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.56 99th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2026-33824 is a critical-severity Double Free (CWE-415) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities 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-2026-33824 is a double free vulnerability (CWE-415) in the Windows IKE Extension. This flaw affects Windows systems that utilize the IKE Extension component for Internet Key Exchange operations. Published on 2026-04-14T18:17:34.767, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical due to its potential for severe impact.

An unauthorized attacker can exploit this vulnerability remotely over the network without requiring authentication, privileges, or user interaction. Exploitation triggers a double free condition, enabling arbitrary code execution on the target system and resulting in high impacts to confidentiality, integrity, and availability.

Microsoft provides guidance on this vulnerability through its Security Response Center update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33824.

EU & UK References

Vulnerability Data

Double free in Windows IKE Extension allows an unauthorized attacker to execute code over a network.

CWE(s)
KEV Date Added
18 August 2026

Related Threats

MITRE ATT&CK Enterprise Techniques

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
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.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33838Same product: Microsoft Windows 10 1607
CVE-2026-34341Same product: Microsoft Windows 10 1607
CVE-2026-32170Same product: Microsoft Windows 10 1607
CVE-2026-26163Same product: Microsoft Windows 10 1607
CVE-2026-21530Same product: Microsoft Windows 10 1607
CVE-2026-20832Same product: Microsoft Windows 10 1607
CVE-2026-62889Same product: Microsoft Windows 10 1607
CVE-2025-59505Same product: Microsoft Windows 10 1607
CVE-2026-32069Same product: Microsoft Windows 10 1809
CVE-2026-32074Same product: Microsoft Windows 10 1809

Affected Assets

microsoft
windows 10 1607
≤ 10.0.14393.9060 · ≤ 10.0.14393.9060
microsoft
windows 10 1809
≤ 10.0.17763.8644 · ≤ 10.0.17763.8644
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 11 26h1
≤ 10.0.28000.1836 · ≤ 10.0.28000.1836
microsoft
windows server 2016
≤ 10.0.14393.9060
microsoft
windows server 2019
≤ 10.0.17763.8644
+3 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)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation explicitly includes dynamic analysis and fuzzing that locate double-free defects before release.

Security engineering principles can require memory-safe allocation patterns or language features that structurally eliminate double-free opportunities.

Flaw remediation processes require identification and correction of memory-management defects such as double free once discovered.

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 SDLC practices directly prevent double-free errors via static analysis, safe memory APIs, and testing.

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.

finds

Security testing in development can detect double-free conditions before release.

prevents

Secure development life cycle includes memory-safety practices that can prevent double-free bugs.

prevents

Application security requirements can mandate memory-safety rules that reduce double-free risk.

prevents

Secure system architecture and engineering principles can prescribe safe memory-management patterns.

prevents

Secure coding standards directly address proper use of free() and similar functions.

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-248590 OL 8 must clear the page allocator to prevent use-after-free attacks. prevents CWE-415

References