CVE-2026-33824Known exploitationPublic exploitNetwork attack vector

Unauthenticated code execution via IKEv2 fragment double-free

Published Apr 14, 2026 · Updated Apr 14, 2026

Double free in Microsoft Windows IKE Extension allows remote attackers to execute arbitrary code through crafted IKEv2 packets. During fragment reassembly, IkeQueueRecvRequest shallow-copies a Security Realm blob pointer, so packet-context and association cleanup free the same allocation. Exploitation requires an IKE_SA_INIT request with the Security Realm Vendor ID followed by fragmented invalid IKE_AUTH traffic, granting SYSTEM-context execution or crashing IKEEXT.

CVSS severity9.8
Critical
EPSS probability72.69%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in Microsoft Windows IKE Extension allows remote attackers to execute arbitrary code through crafted IKEv2 packets. During fragment reassembly, IkeQueueRecvRequest shallow-copies a Security Realm blob pointer, so packet-context and association cleanup free the same allocation. Exploitation requires an IKE_SA_INIT request with the Security Realm Vendor ID followed by fragmented invalid IKE_AUTH traffic, granting SYSTEM-context execution or crashing IKEEXT.

The record

CVE
CVE-2026-33824
Published
Apr 14, 2026
Updated
Apr 14, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-415, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 2026Record updatedLatest update available in the CVE record.
  3. Aug 18, 2026Exploitation reportedCISA Known Exploited Vulnerabilities listing

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.17763.0 <10.0.17763.8644

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.8644
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32690
Microsoft · Windows 11, version 25H2version=10.0.26200.0 <10.0.26200.8246
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.9060
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.32690
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.7184
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.2274
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.9060
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.6936
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.7184
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.8644
Microsoft · Windows 11, version 26H1version=10.0.28000.0 <10.0.28000.1836
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.6936
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.9060
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.5020
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32690
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.8644

Published CVSS scores

9.8Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-415Double Free
T1210Exploitation of Remote Services

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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