---
title: "DRM License Server 5.11.5"
description: "This release updates the Widevine Server SDK to version 19.15.1 with support for Widevine License Release requests, and enhances License Cipher security to block unauthorized requests."
---
> For the complete documentation index, see [llms.txt](/llms.txt).

## Widevine Server SDK v19.15.1 Integration

- Updated core DRM modules to leverage the latest Widevine Server SDK version 19.15.1.
- Added full support for Widevine License Release Requests, enabling seamless handling of license release and revocation payloads sent from client devices (CDMs) upon session termination or persistent license cleanup.

## Enhanced License Cipher Security & Validation

- Updated internal License Cipher validation logic to detect and block unauthorized or abnormal license requests originating from OpenWV environments.
- Strengthened security against unauthorized DRM requests and non-compliant client modules.