Hydra security shutdown

Updated on 16/09/2025

Access to Hydra is open again: both the portal and the login nodes are now online.

All critical systems have been patched with the necessary security updates, and we have no indication that any breach of security has occurred. Most worker nodes are already available, and the few remaining ones will be back shortly.

During this downtime, we also took the opportunity to perform several maintenance tasks on the cluster. If you experience any issues with the updated system, please contact us at VUB-HPC Support.

Updated on 15/09/2025

The team has been working through the weekend to ready the software updates needed to fix the security vulnerabilities disclosed last week. At this time all fixes are ready for deployment. We will not interrupt any running jobs though, so nodes in the cluster will be upgraded as soon as they become empty.

We expect to put login nodes back online later today and the full Hydra cluster probably tomorrow.

We can confirm that the security of the Hydra has not been compromised.

We have shut down access to Hydra on Sep 12th at 14:00: both the login nodes and the portal are not accessible until further notice.

A serious security flaw in the Linux kernel has been recently disclosed, which reportedly is being actively exploited. We have no indication that the security of the cluster has been compromised; this shutdown is out of caution.

The same action has been taken by other VSC clusters as well. You can check the current status of all clusters in status.vscentrum.be.

We are working on upgrading all our systems to fix the flaw. As soon as this is done, the cluster will be available again. If all goes well, the systems should be back up at the beginning of next week.

You can still access your data through Globus.

If you have any questions, contact us at VUB-HPC Support.