Always On VPN IKEv2 Security Vulnerability April 2026

Microsoft published its Security Updates for April 2026 today, and the good news is that there are no Windows Server Routing and Remote Access (RRAS) vulnerabilities this month. However, they disclosed a critical remote code execution (RCE) vulnerability that impacts deployments using Internet Key Exchange version 2 (IKEv2).

IKE Service Extensions RCE

CVE-2026-33824 addresses a security vulnerability in the Windows Internet Key Exchange (IKE) Service Extensions. This vulnerability is a Remote Code Execution (RCE) vulnerability, with a CVSS 3.1 base score of 9.8 (Critical). Always On VPN implementations that use the device tunnel or IKEv2 for the user tunnel are affected.

Impact

This vulnerability presents a unique challenge to Always On VPN administrators as IKEv2 is required to support device tunnel connections. Some implementations also use IKEv2 for the user tunnel. In either case, the vulnerable VPN server, often domain-joined, is reachable from the Internet, greatly increasing the attack surface and exposure to this vulnerability.

Recommendations

For deployments that use IKEv2 (device or user tunnel), administrators should update their RRAS server as soon as possible to protect against potential attacks on this service.

Not Using IKEv2?

If you are not using the device tunnel or IKEv2 for the user tunnel, ensure the following IKEv2 ports are blocked at the edge firewall.

  • Inbound UDP port 500 (IKE)
  • Inbound UDP port 4500 (IKE NAT-T)

In addition, consider disabling IKEv2 on the RRAS server by opening an elevated command window and running the following command.

netsh.exe ras set wanports device = "WAN Miniport (IKEv2)" rasinonly = disabled ddinout = disabled ddoutonly = disabled maxports = 0

Optionally, you can use the Routing and Remote Access management console (rrasmgnt.msc) to perform this task.

  1. Right-click on Ports and choose Properties.
  2. Select WAN Miniport (IKEv2).
  3. Click Configure.
  4. Uncheck Remote access connections (inbound only).
  5. Uncheck Demand-dial routing connection (inbound and outbound).
  6. Enter 0 in the Maximum ports field.
  7. Click Ok.

Additional Information

Microsoft Security Updates for April 2026

CVE-2026-33824 – Windows Internet Key Exchange (IKE) Service Extension RCE

What’s New in Absolute Secure Access v14

Absolute Software recently announced a significant upgrade for its popular secure remote access and Zero Trust Network Access (ZTNA) solution. Version 14 of Secure Access introduces many compelling new features and updates that administrators will find beneficial. In addition, crucial security vulnerabilities in the previous release have been addressed.

New Features

Absolute Secure Access v14.x includes many enhancements over previous releases. Here are a few of the highlights.

Improved Performance

Absolute Secure Access v14 provides much faster throughput on multi-gigabit networks (e.g., 2.5Gbps Wi-Fi 6E/7 or 10Gbps wired). New kernel-level optimizations reduce CPU overhead by up to 40% on high-speed links, improving performance on faster networks.

Modern Certificate Handling

SHA-1 has been deprecated since 2011, and beginning with Absolute Secure Access v14, support for SHA-1 certificates has been removed completely.

Enhanced Client Auto Reconnect

Improved client auto-reconnect logic now survives Windows standby mode for more than 12 hours (previous versions were capped at around 4 hours). This will reduce frustration when devices return from standby for extended periods.

Automatic Host Group Updates

Host groups are an excellent way to streamline policy configuration for services like Microsoft 365 and AWS. These cloud providers publish the IP addresses of their services, which are dynamic and often change over time. Absolute Secure Access v14 now supports automatic host group updates for these services. Microsoft 365 updates occur every 28 days, and AWS updates occur every 5 days by default. This interval is configurable for administrators.

Security Updates

Absolute Secure Access v14 closes four server-side CVEs as well as 14 third-party CVEs (Apache, OpenSSL, etc.) that were not patched in v13.x.

Summary

If you have deployed previous versions of Absolute Secure Access, consider upgrading to v14.x today. You’ll gain improved performance, reduced administrative overhead, critical security updates, and much more. If you’d like help with your migration or want to learn more about the new capabilities in Absolute Secure Access v14, fill out the form below, and I’ll provide more information.

Additional Information

Absolute Secure Access

Absolute Secure Access Enterprise VPN Advanced Features In Depth

Absolute Secure Access and IPv6

Always On VPN Security Updates July 2025

Patch Tuesday has arrived, and, unlike last month, it’s a busy month for Always On VPN administrators. The June 2025 Microsoft security updates address a whopping 16 (!) vulnerabilities in the Windows Routing and Remote Access Service (RRAS). Notably, DirectAccess administrators are once again impacted by a critical vulnerability in the Windows KDC Proxy Service (KPSSVC) this month.

RRAS

As stated previously, this month’s update addresses 16 unique CVEs in Windows Server RRAS. All are memory-related buffer overflows and out-of-bounds reads, indicating that a security researcher was recently probing for vulnerabilities in RRAS.

While all the above CVEs are Remote Code Execution (RCE) and Information Disclosure vulnerabilities, none are rated as Critical; all are rated as Important. This means exploitation is unlikely, but administrators are encouraged to update as soon as possible.

KDC Proxy

This month’s security update includes another Critical RCE in the Windows KDC Proxy Service (KPSSVC).

The KDC Proxy is enabled by default when DirectAccess is configured. By design, this means the service is exposed to the public Internet, posing a significant risk to organizations using DirectAccess for secure remote access. Administrators are urged to update their systems immediately to avoid compromise.

Additional Information

Microsoft July 2025 Security Updates