CVE Intelligence
CISA KEV Critical Memory corruption

CVE-2026-33824 — Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability

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

Published Apr 14, 2026 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: microsoft

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (github)+6
  • EPSS 1.6% (30-day exploitation probability)+11
  • Technical severity (critical)+10
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Aug 18, 2026
EPSS FIRST
1.62%
ahead of 76% of scored CVEs · Oct 14, 2026
Affects
Microsoft
Windows 10 1607 and 24 more
CVSS base
9.8
Critical · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

US federal deadline: Aug 21, 2026 — passed 55 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  5. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Microsoft Windows 10 1607 < 10.0.14393.9060 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 1809 < 10.0.17763.8644 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 21h2 < 10.0.19044.7184 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 22h2 < 10.0.19045.7184 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 Version 1607 ≥ 10.0.14393.0 and < 10.0.14393.9060 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 1809 ≥ 10.0.17763.0 and < 10.0.17763.8644 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 21H2 ≥ 10.0.19044.0 and < 10.0.19044.7184 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 22H2 ≥ 10.0.19045.0 and < 10.0.19045.7184 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 11 23h2 < 10.0.22631.6936 Vulnerable NIST National Vulnerability Database
Microsoft Windows 11 24h2 < 10.0.26100.8246 Vulnerable NIST National Vulnerability Database
Microsoft Windows 11 25h2 < 10.0.26200.8246 Vulnerable NIST National Vulnerability Database
Microsoft Windows 11 26h1 < 10.0.28000.1836 Vulnerable NIST National Vulnerability Database
Microsoft Windows 11 version 23H2 ≥ 10.0.22631.0 and < 10.0.22631.6936 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 11 Version 24H2 ≥ 10.0.26100.0 and < 10.0.26100.8246 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 11 Version 25H2 ≥ 10.0.26200.0 and < 10.0.26200.8246 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 11 version 26H1 ≥ 10.0.28000.0 and < 10.0.28000.1836 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2016 < 10.0.14393.9060 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2016 ≥ 10.0.14393.0 and < 10.0.14393.9060 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2016 (Server Core installation) ≥ 10.0.14393.0 and < 10.0.14393.9060 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2019 ≥ 10.0.17763.0 and < 10.0.17763.8644 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2019 < 10.0.17763.8644 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2019 (Server Core installation) ≥ 10.0.17763.0 and < 10.0.17763.8644 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2022 ≥ 10.0.20348.0 and < 10.0.20348.5020 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2022 < 10.0.20348.5020 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2022 23h2 < 10.0.25398.2274 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) ≥ 10.0.25398.0 and < 10.0.25398.2274 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2025 ≥ 10.0.26100.0 and < 10.0.26100.32690 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2025 < 10.0.26100.32690 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2025 (Server Core installation) ≥ 10.0.26100.0 and < 10.0.26100.32690 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.1 Critical 3.9 5.9 secure@microsoft.com via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
9.8 CVSS 3.1 Critical — — microsoft via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: secure@microsoft.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-415 · Double Free

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Aug 18, 2026
Federal deadline
Aug 21, 2026
passed 55 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 1.62%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
  • Hunt retroactively in logs from before Aug 18, 2026 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · microsoft/windows 10 version 1607, microsoft/windows 10 version 1809, microsoft/windows 10 version 21h2, microsoft/windo
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Affected products added · microsoft/windows 10 1607, microsoft/windows 10 1809, microsoft/windows 10 21h2, microsoft/windows 10 22h2, microsoft/wi
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Added to CISA KEV catalog
    Aug 17, 2026 · CISA
  • CVE published
    Apr 14, 2026 · microsoft

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

6 on the record

Elsewhere on this site

Microsoft
every CVE for this vendor
2026-08
what else CISA listed that month
CWE-415
other pages naming this weakness

Related CVEs (same products)

  • Medium CVE-2026-97844 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97839 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97840 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97841 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97842 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97843 Role: DNS Server Information Disclosure Vulnerability 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-33824 is "Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability", rated Critical. It affects Windows 10 1607 (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 1.62% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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