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

What it is

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

Exploitation evidence

First exploit evidence seen: 2026-08-18 (earliest date across the sources below).

Exploited in the wild

• CISA KEV: listed since 2026-08-18. Source

Public exploit code

GitHub proof-of-concept repositories below quality bar

2 public repositories from 2 accounts, first seen 2026-04-21.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · nomi-sec/PoC-in-GitHub.

How to fix it

CISA required action

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. (source: CISA KEV)

Fixed versions

• microsoft windows 10 1607: upgrade to 10.0.14393.9060 or later
• microsoft windows 10 1809: upgrade to 10.0.17763.8644 or later
• microsoft windows 10 21h2: upgrade to 10.0.19044.7184 or later
• microsoft windows 10 22h2: upgrade to 10.0.19045.7184 or later
• microsoft windows 11 23h2: upgrade to 10.0.22631.6936 or later
• microsoft windows 11 24h2: upgrade to 10.0.26100.8246 or later
• microsoft windows 11 25h2: upgrade to 10.0.26200.8246 or later
• microsoft windows 11 26h1: upgrade to 10.0.28000.1836 or later
• microsoft windows server 2016: upgrade to 10.0.14393.9060 or later
• microsoft windows server 2019: upgrade to 10.0.17763.8644 or later
• microsoft windows server 2022: upgrade to 10.0.20348.5020 or later
• microsoft windows server 2022 23h2: upgrade to 10.0.25398.2274 or later
• microsoft windows server 2025: upgrade to 10.0.26100.32690 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-33824 (CISA KEV notes)
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33824 (Vendor Advisory)

Detection Generic guidance

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.