The Hyperion Product Management recently advised the release of Patch Set Updates (PSU) for Oracle Hyperion Essbase 11.1.2.4.x.
These PSU downloads are available from the 
My Oracle Support | Patches & Updates section.
Hyperion Essbase Server 11.1.2.4.005
Patch 22091661: Essbase Server
Hyperion Essbase Client 11.1.2.4.005Patch 22091665: Essbase RTC
Patch 22091652: Essbase Client
Patch 22091644: Essbase MSI
Hyperion Essbase Administration Services (EAS) 11.1.2.4.005
Patch 22106770: EAS Server
Patch 22106776: EAS Console
Hyperion Analytic Provider Services (APS) 11.1.2.4.005
Patch 22111912: APS Services
Hyperion Essbase Studio 11.1.2.4.005
Patch 22111935: Essbase Studio Server
Patch 22111943: Essbase Studio Console MSI
These PSU releases can be applied to the following releases of existing Essbase installations:
11.1.2.4.000
11.1.2.4.001
11.1.2.4.002
11.1.2.4.003
11.1.2.4.004*
Note: *Versions listed may not have been released for all Essbase components
RECOMMENDATION:
Oracle recommends using the same version of all Essbase portfolio products (Essbase, Essbase Administration Services, Hyperion Provider Services, and Essbase Studio) and components (server, client, runtime client, API, and JAPI). When only some Essbase portfolio products are included in a patch release, the last released versions of the products that are not included in the patch are supported.
After a patch is applied within the same release codeline, Oracle recommends as a best practice that you export the data from your databases, clear the data from the databases, and then reload the data.
DOCUMENTATION:
Oracle Help Center provides the Enterprise Performance System (EPM) 11.1.2.4 documentation, with the guides including Deployment & Installation, Best Practices, Accessibility Guides and more.
The Hyperion Essbase 11.1.2.4 product specific guides are located within Oracle Applications - Business Analytics section:
Oracle Help Center | Oracle EPM System Documentation 11.1.2.4
README FILE:
Refer to the Readme files prior to proceeding with these PSU implementations for important information that includes the supported paths per component, along with a full list of the defects fixed, additional support information, prerequisites, details for applying patch and troubleshooting FAQ's.
It is important to ensure that the requirements and support paths to this patch are met as outlined within the Readme file.
The Readme file is available from the Patches & Updates download screen for each of the Hyperion Essbase components.
To locate the latest Essbase Patch Sets and Patch Set Updates at anytime visit the My Oracle Support (MOS) Knowledge Article:
Available Patch Sets and Patch Set Updates for Oracle Hyperion Essbase
Doc ID 1396084.1
Why not share your experience about installing this patch ...
In the MOS | Patches & Updates screen for the relevent patch, simply click the "Start a Discussion" and submit your review.
The patch install reviews and other patch related information is available within the My Oracle Support Communities. Visit the Oracle Hyperion EPM sub-space:
Hyperion Patch Reviews
For questions specific to Hyperion Essbase ...
The My Oracle Support Community "Hyperion Essbase" is the ideal first stop to seek & find product specific answers:
Hyperion Essbase