Today is September 16, 2025. If you're reading this and still running MCR 23.0, you've got exactly 260 days before your container runtime becomes an unsupported security liability. That might sound like plenty of time, but factor in procurement cycles, change management bureaucracy, and the inevitable "why is this taking so long" questions from management, and you're already behind schedule.
The dirty truth is that most enterprise teams don't start planning upgrades until three months before EOL, then spend the last month in panic mode trying to get emergency budget approval. Don't be that team.
Why This EOL Actually Matters (Unlike Most Software)
Docker vulnerabilities are public domain knowledge the moment they're disclosed. When CVE-2024-XXXXX drops and affects container runtimes, you've got maybe 72 hours before security scanners start flagging your infrastructure. Running an EOL container runtime means you're betting your career that no new Docker vulnerabilities will be discovered after June 2025.
That's not a bet any rational engineer makes.
MCR 20.10 went EOL in December 2023, and teams still running it have already been exposed to multiple unpatched vulnerabilities. Don't repeat their mistakes.
The Hidden Costs of Procrastination
The Mirantis support team won't take your tickets if you're running EOL software. That $50K/year support contract becomes worthless the day your version hits end-of-life. Your production containers start crashing on a weekend? Good luck with Stack Overflow. Mirantis support response time is actually 2-4 hours (not their claimed 1 hour), but that still beats the hell out of debugging containerd networking issues yourself.
Compliance auditors are even less forgiving. NIST container security guidelines require supported software versions for any system handling sensitive data. Running EOL MCR in a regulated environment is audit failure waiting to happen.
The MCR 25.0 Upgrade Reality
MCR 25.0 isn't a revolutionary change - it's Docker with enterprise polish and support that actually works. The upgrade path from 23.0 is deliberately straightforward because Mirantis learned from Docker's history of breaking changes.
What stays the same:
- All your Dockerfiles work unchanged
- docker-compose.yml files need zero modifications
- Same CLI commands, same API endpoints
- FIPS 140-2 validation carries forward
- Windows container support (still a nightmare, but a working nightmare)
What actually improves:
- CVE patching timeline drops from months to weeks
- Better memory management for large container deployments
- Improved Windows Server 2022 compatibility (containers actually start)
- More reliable container startup on Ubuntu 22.04
- MCR version checks don't fail silently if your license is expired anymore
The biggest challenge isn't technical - it's organizational. Getting budget approval, scheduling maintenance windows, and coordinating with application teams takes longer than the actual upgrade.
Alternative Exit Strategies
If paying $1,125/node/year for Docker feels wrong, this EOL deadline is your escape opportunity. Present management with a side-by-side cost analysis: another year of Mirantis licensing versus migrating to standard Kubernetes.
The OpenShift Option: Red Hat OpenShift costs 3x more but includes enterprise Kubernetes, monitoring, CI/CD, and support that's actually useful. If you're already paying enterprise prices, might as well get enterprise capabilities.
The DIY Kubernetes Route: Vanilla Kubernetes with containerd gives you the same container capabilities without licensing fees. But factor in the operational overhead - you're now responsible for cluster management, security patching, and support.
The Docker CE Gamble: Docker Community Edition is free but comes with zero support and community-driven security patching. Fine for startups, career-limiting for enterprises.
Planning Your Migration Timeline
Month 1-2 (October-November 2024): Build the business case. Get budget approval. Schedule pilot upgrades.
Month 3-4 (December 2024-January 2025): Test MCR 25.0 in non-production. Document the upgrade process. Train your team.
Month 5-6 (February-March 2025): Execute production upgrades during scheduled maintenance windows. One environment at a time.
Month 7-8 (April-May 2025): Complete remaining systems. Buffer time for unforeseen issues.
June 4, 2025: Sleep peacefully knowing you're not running EOL infrastructure.
The teams that start planning now will have smooth, scheduled upgrades. The teams that wait until March will be paying emergency consulting rates and explaining production outages to angry stakeholders.