containerd

api/v1.11.0Kubernetes Core

Apr 30, 2026Copy link

containerd API v1.11.0 ships a new shim bootstrap protocol, container filesystem copy transfer types, and sandbox spec field support — aligning with the containerd 2.3 runtime release.

• breakingSandbox API: Container field removed, update any sandbox metadata consumers

  The Container field has been dropped from sandbox metadata and replaced with a spec field. If you have tooling, controllers, or custom runtimes that read or write sandbox metadata directly, audit them now. This is an API-level change — anything compiled against the old proto definitions will break at runtime when targeting containerd 2.3.

• breakingShim bootstrap protocol is now protobuf — custom shim implementations need updating

  The new shim bootstrap protocol switches from JSON to protobuf and uses enums instead of strings for capabilities and log levels. If you maintain a custom shim or vendor the containerd API, you must update your bootstrap handling before deploying containerd 2.3. Third-party shims (e.g., kata-containers, nydus) likely need corresponding releases — check their compatibility before upgrading.

• securitygRPC updated from v1.59.0 to v1.79.3 — multiple CVE fixes included

  A 20-minor-version jump in gRPC covers a significant span of security and stability fixes. If your environment pins or vendors gRPC separately, reconcile your dependency tree against v1.79.3. The golang.org/x/* packages also moved forward across the board, so a full dependency audit is warranted before deploying this API version in production.