# JetBrains Releases Critical Security Updates Across Multiple MPS Versions New patches address compromised certificates and introduce toolkit improvements for MPS developers. - **Source:** [The JetBrains Blog](https://brifing.si/source/782eebd1-7be8-49cc-b27c-e552516691b2) - **Published:** 2026-11-02 - **Topic:** [Software & Engineering](https://brifing.si/c/engineering) - **Original article:** - **On Brifing:** https://brifing.si/s/20e3bf9e-58b7-4277-8785-8ad4fb63e527 ## Critical Security Patch Deployment JetBrains has released urgent updates for MPS versions 2026.2 RC2, 2026.1.2, 2025.3.3, 2025.2.5, and 2025.1.5. These releases primarily address a critical security vulnerability linked to compromised eMudhra certificates. Users are strongly advised to review the dedicated security blog post to understand the specific risks and necessary mitigation steps for their environments. ## Mandatory JCEF Configuration Changes For users operating on versions 2025.1.5 or 2025.2.5, a specific manual intervention is required to maintain security. You must disable JCEF by toggling the ide.browser.jcef.enabled flag within the MPS Registry. This action is essential because the underlying JBR and JCEF components are directly impacted by the identified security vulnerability affecting the IDE. ## Impact on RCP Applications The security issue extends beyond the core IDE, potentially affecting all MPS-based RCP applications. Developers who build and distribute these applications must perform all recommended security actions to ensure their software remains protected. Failure to address these components could leave distributed RCP applications vulnerable to the same certificate-related security risks identified. ## Projectional Agent Toolkit Enhancements MPS versions 2026.1.2 and 2026.2 RC2 include significant upgrades to the Projectional Agent Toolkit plugin. These improvements incorporate features originally planned for the 2026.2 release cycle. Developers should ensure they prompt their agents to update project skills to fully leverage these new capabilities, which include consolidated MCP tool APIs and performance optimizations. ## Toolkit Performance and API Updates The updated toolkit introduces numerous performance improvements and a refined type system for MCP tools. Key functional additions include automatic skill database updates, enhanced access to MPS logs, and improved management of MPS projects. These changes aim to streamline development workflows by providing more robust tools for handling complex SModel expressions and Java statements. ## Intention Actions and Fixes New intention actions and quick-fixes are now available within the updated Projectional Agent Toolkit. These tools facilitate the automatic correction of SModel expressions found in parsed Java statements, reducing manual debugging time. By integrating these features, the update enhances the overall stability and efficiency of the development environment for all MPS users. ## Version Specific Update Scope While the 2026 series receives both security patches and toolkit enhancements, the 2025 versions—specifically 2025.3.3, 2025.2.5, and 2025.1.5—are limited to the critical security fixes. This distinction ensures that legacy version users receive the necessary protection against the certificate compromise without requiring a migration to the newer, feature-rich 2026.x development branch. ## Maintaining Secure Development Environments These releases highlight the importance of rapid response to certificate-related vulnerabilities in IDE ecosystems. By providing clear instructions for both manual configuration and software updates, JetBrains aims to minimize disruption. Developers should prioritize these patches immediately to secure their build pipelines and ensure the integrity of their distributed RCP application deployments. ## Sources covering this story - https://blog.jetbrains.com/mps/2026/11/mps-2026-1-2-released/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._