Update Xen hypervisor to v4.21
XenServerCitrix
Normal channel updates
May 25, 2026
Checksum: 2efe82f761eb4c025456f998caaca802fd9f6d40b9919356c128a1ca5cc73726
These updates include security fixes. For more information, see the Security
Bulletins CTX696527, CTX696562 and CTX696581.
These updates contain the following improvements:
- Update Xen hypervisor to v4.21
- Update the device model (QEMU) to v10.1.
- Update the Intel microcode to the IPU 2026.2 drop.
- Update the intel-ice driver to v2.4.5.
- Add mpt3sas driver.
These updates include fixes for the following issues:
- Under extremely rare conditions VMs may start without disks attached.
- In some cases AD user login can fail due to a failure to retrieve subject details.
- In some cases attempting to join a freshly installed host to an existing pool may fail with a POOL_JOINING_SM_FEATURES_INCOMPATIBLE error.
- In rare circumstances following a host crash the crashdump process can ‘hang’ and the machine does not reboot.
- Live patches that were not applicable may be incorrectly reported as applicable on hosts.
- The audit log endpoint does not return data if a request is made using the since parameter.
