Listen to this Post
CVE-2026-33824 is a critical remote code execution vulnerability affecting the Windows Internet Key Exchange (IKE) Service Extensions. The vulnerability resides in ikeext.dll, a core component of the Windows network protocol stack responsible for handling IPsec VPN key exchanges. It is classified as a CWE-415: Double Free weakness, where the software calls `free()` twice on the same memory address, potentially leading to the modification of unexpected memory locations.
An unauthenticated, remote attacker can exploit this vulnerability by sending specially crafted packets to a target Windows machine that has Internet Key Exchange (IKE) version 2 enabled. The attack is initiated over the network through UDP ports 500 or 4500, with no user interaction or privileges required. Successful exploitation allows the attacker to execute arbitrary code on the target system with the highest privileges.
Microsoft addressed this vulnerability during the April 2026 Patch Tuesday, releasing security updates for all supported Windows 10, Windows 11, and Windows Server releases. Despite the patch being available for months, CISA added CVE-2026-33824 to its Known Exploited Vulnerabilities (KEV) catalog on August 18, 2026, confirming active exploitation in the wild. The vulnerability has been linked to a Chinese-speaking threat actor as part of an AI-enabled autonomous hacking campaign.
With a CVSS v3.1 base score of 9.8 (CRITICAL) and an EPSS score indicating a high likelihood of exploitation (56% to 99% percentile), this flaw poses a significant risk to federal enterprises and private organizations alike. CISA has mandated that U.S. Federal Civilian Executive Branch agencies patch this vulnerability within three days under Binding Operational Directive 26-04.
DailyCVE Form:
Platform: Windows 10/11/Server
Version: All supported versions
Vulnerability: Double Free (CWE-415)
Severity: CRITICAL (CVSS 9.8)
Date: April 14, 2026
Prediction: Already Patched (April 2026)
What Undercode Say:
Analytics
- CISA KEV Addition: August 18, 2026
- Active Exploitation: Confirmed in the wild
- Threat Actor: Chinese-speaking group in AI-enabled campaign
- Exploit Price Estimate: $25,000 – $100,000
- Nessus Plugin ID: 306454
Exploit: (Educational Purposes!)
Scan for vulnerable IKE service on UDP ports 500 and 4500
nmap -p 500,4500 -sU --script ike-version <target-ip>
Example of a crafted IKE packet payload structure
This is a simplified representation - actual exploit requires deep
reverse engineering of ikeext.dll memory management routines
Python snippet illustrating double free trigger concept
import socket
target = ("<target-ip>", 500)
payload = b"\x00" 1024 Crafted IKE packet with malformed structure
First free() occurs during parsing, second free() on same address
during error handling - leading to use-after-free conditions
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(payload, target)
Protection
1. Apply the April 2026 security update immediately
- Block inbound traffic on UDP ports 500 and 4500 for systems not using IKE
- Configure firewall rules to allow inbound IKE traffic only from known peer addresses
- Disable IKEv2 if not required by business operations
- Use Nessus plugin ID 306454 to detect vulnerable systems
Impact
- Confidentiality, Integrity, Availability: Complete system compromise (all three CIA metrics rated HIGH)
- Attack Vector: Network-based, remotely exploitable
- Authentication: None required (PRE: N)
- User Interaction: None required (UI: N)
- Affected Products: All supported Windows 10, Windows 11, and Windows Server releases
- Federal Mandate: Must be patched within 3 days per BOD 26-04
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: www.cve.org
Extra Source Hub:
Undercode
