Security update: Critical Java patch update

Incident Report for Mendix Technology

Update

The fix for Java 17 has been released and rolled out across Mendix Cloud. If your app is running on Java 17, please follow the redeploy instructions as listed in the original statuspage message. For Java 11, we're waiting for an update from our vendors. Once these updates are available, we will update the Java versions used on Mendix Cloud.
Posted Oct 28, 2026 - 09:31 UTC

Identified

What happened
On 20 October 2026, Oracle has released an October 2026 Critical Patch Update (https://blogs.oracle.com/security/october-2026-critical-patch-update-released) that includes multiple fixes for Java versions that are in use by Mendix apps.

Who is affected
All customers with applications running on Mendix Cloud.

What we did
We have updated the Java version for Java 25, Java 21 and Java 17. These new versions include the critical patch updates.
For Java 11, we're waiting for an update from our vendors. Once these updates are available, we will update the Java versions used on Mendix Cloud.

What you need to do
If your app is running on Java 17, 21 or Java 25, you should redeploy your app. You can find the Java version used for your environment on the Environment Details page (https://docs.mendix.com/developerportal/deploy/environments-details/#application-status). You can redeploy the same package that is already running on your environment, or build and deploy a new package. A restart is not enough!

We recommend doing this in your usual order, so you can check that your applications still work before updating production:
1. Test environment
2. Acceptance environment
3. Production environment

If your app is running on Java 11, you should keep an eye on this Statuspage incident. We will update this when we release new Java versions on Mendix Cloud. These updates will include instructions for the specific Java versions.

Deployment requirements
To apply these security fixes, you must perform a regular deployment (non-Zero Downtime Deployment). Zero Downtime Deployment (ZDT) will not apply these security fixes, even when redeploying an existing deployment package. You do not need to create a new deployment package. You can redeploy your existing package using the regular deployment process. If you have already performed a Zero Downtime Deployment to apply these fixes, please redeploy using the regular deployment process. A regular deployment causes a short period of downtime while the application restarts, so please plan accordingly.

If you have any questions, feel free to contact support.
Posted Oct 23, 2026 - 13:22 UTC
This incident affects: Mendix Cloud Regions (Mendix Cloud US-East, Mendix Cloud EU (Frankfurt), Mendix Cloud Asia Pacific (Tokyo), Mendix Cloud Free Tier EU, Mendix Cloud UK, Mendix Cloud IE, Mendix Cloud US-West, Mendix Cloud Asia Pacific (Sydney), Mendix Cloud Canada (Central), Mendix Cloud Asia Pacific (Singapore), Mendix Cloud Asia Pacific (Mumbai), Mendix Cloud Africa (Cape Town), Mendix Cloud South America (São Paulo), Mendix Cloud EU (Frankfurt 2), Mendix Cloud Asia Pacific (Osaka), Mendix Cloud Asia Pacific (Seoul), Mendix Cloud Asia Pacific (Jakarta), Mendix Cloud EU (Frankfurt): GenAI Resources, Mendix Cloud Canada (Central): GenAI Resources) and Mendix Cloud Dedicated Regions (Mendix Cloud Dedicated US-West Echo, Mendix Cloud Dedicated UK Echo, Mendix Cloud Dedicated Asia Pacific (Singapore) Echo, Mendix Cloud Dedicated US-East Hotel, Mendix Cloud Dedicated US-East Mike, Mendix Cloud Dedicated US-East Papa, Mendix Cloud Dedicated EU (Frankfurt) Sierra, Mendix Cloud Dedicated EU (Frankfurt) Uniform, Mendix Cloud Dedicated Asia Pacific (Singapore) Able, Mendix Cloud Dedicated US-East Kilo, Mendix Cloud Dedicated US-East Charlie, Mendix Cloud Dedicated US-East Colin, Mendix Cloud Dedicated EU (Frankfurt) Metro).