Developer Enablement Briefing — November 12, 2025
Google Cloud Functions retires the first-generation .NET 6 runtime on 12 November 2025, forcing platform teams to shift critical workloads onto .NET 8 or second-generation deployments before executions are blocked.
Executive briefing: Google Cloud will decommission the first-generation Cloud Functions dotnet6 runtime on , removing the google-22 images that still host .NET 6 workloads.1 Any function that has not migrated to .NET 8 or a second-generation deployment by that date will lose the managed execution environment, stranding CI/CD pipelines, event triggers, and scheduled jobs that still pin to .NET 6.
The retirement lands a year after Microsoft’s long-term support window for .NET 6 closed on , leaving organisations without upstream security patches throughout the final Cloud Functions grace period.2 Maintaining workloads on the deprecated runtime effectively doubles the blast radius: Google can shut down containers in November 2025 while Microsoft has already stopped shipping CVE fixes.
Impact on platform and product teams
- Serverless cold starts and buildpacks: First-generation deployments tied to
google-22base images will fail to build or invoke once the runtime ID is removed; release engineers must switch todotnet8or migrate to second-generation functions that run on Cloud Run infrastructure.1 - Library compatibility debt: Many .NET open-source packages already target .NET 8 as the minimum LTS; staying on .NET 6 prevents teams from consuming security updates and new features across identity, observability, and data-access SDKs.
- Pipeline security: Continuing to deploy .NET 6 binaries after November 2024 forces security teams to create compensating controls for unpatched CVEs, undermining SOC 2 and ISO 27001 attestations.
Actions to complete before the cutoff
- Refactor build configurations to target .NET 8 and retest triggers (Pub/Sub, Cloud Scheduler, Eventarc) under the new runtime, validating start-up latency and memory footprint.
- Migrate critical workloads to second-generation functions or Cloud Run services to take advantage of regional availability, concurrency controls, and Cloud Build packaging.
- Retire legacy dependencies that still enforce .NET 6, replacing them with LTS-compatible libraries and documenting risk acceptance for any vendor components that lack .NET 8 support.
- Update observability baselines—cold start metrics, error budgets, and IAM bindings—to reflect the runtime swap and satisfy compliance sign-offs before the November 2025 shutdown window.