SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-33824

Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability

KEVCRITICAL 9.8EPSS 72.7%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 21 August 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
72.69% probability · 99th percentile
CISA KEV
Listed 18 August 2026 · due 21 August 2026
Weakness
CWE-415
Affected
microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows 11 25h2 · microsoft/windows 11 26h1 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2022 23h2 · microsoft/windows server 2025
Source
secure@microsoft.com

CISA notes

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. https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-33824 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-33824

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.